Employing Associations In Partnership
Market
1 with the biggest keys to a profitable partnership
advertising strategy is relationships. A whole lot of experts as well as
skilled business owners might concur that associations serve as an vital first
step toward business. Being able to funnel its energy and influence is the
reason why the small business proprietor productive. Eventually, superior
relationships equal fantastic business, and nothing is actually more true in
joint endeavors.
In partnership promoting strategies, two things which might be very first regarded as whenever trying to find an excellent partnership companion are needs and relationships. These go hand in hand because it is challenging for the organization owner in order to offer needs to the companion if he or she does not create a relationship using the companion first.
Whenever sketching out a promoting plan, it's essential to very first end up being sure what your business is for, what folks uncover interesting about this in the first place, or even how other firms can use your own small business, possibly prior to or even immediately after prospects use their own company. Your own small business should be presented with regards to revenue and advantage.
Partnership promoting delivers need to end up being uniquely designed for the companion within mind. This really is exactly where you depend on the relationship side of the procedure. With the associations you've designed, you are going to have the ability to fully grasp what is critical for the individual you are speaking with. It is actually after that which you are able to create a winning and convincing supply as well as multiply your enterprise in order to much more investors, shoppers, or affiliate marketers.
Affiliate marketers tend to be the majority of likely compelled to listen if your speech is due to advancement. What does your business obtain that would drive their business enterprise one step further? Exactly what do you might have on their behalf that will make sure they are stand out? You may existing a percentage cut through product sales profits, if your item or even support isn't practical or popular or even associated in any way, they'd the majority of likely change a person lower.
To avoid the poor business enterprise proposal, focus on your own company partners. Give them exactly what they are in search of at a smaller trade as well as let them begin to see the win-win situation with the provide on the table. An example is actually Paypal, that gave Facebook the actual financial support it necessary as a commence up in return for a smaller inventory proportion, and became component of an incredibly prosperous enterprise.
Partnership marketing and advertising tactics making use of associations like a power source entails three points: knowing, deciding on, as well as concentrating. Know which associations would offer you additional worth, select them, and concentrate in it.
In partnership promoting strategies, two things which might be very first regarded as whenever trying to find an excellent partnership companion are needs and relationships. These go hand in hand because it is challenging for the organization owner in order to offer needs to the companion if he or she does not create a relationship using the companion first.
Whenever sketching out a promoting plan, it's essential to very first end up being sure what your business is for, what folks uncover interesting about this in the first place, or even how other firms can use your own small business, possibly prior to or even immediately after prospects use their own company. Your own small business should be presented with regards to revenue and advantage.
Partnership promoting delivers need to end up being uniquely designed for the companion within mind. This really is exactly where you depend on the relationship side of the procedure. With the associations you've designed, you are going to have the ability to fully grasp what is critical for the individual you are speaking with. It is actually after that which you are able to create a winning and convincing supply as well as multiply your enterprise in order to much more investors, shoppers, or affiliate marketers.
Affiliate marketers tend to be the majority of likely compelled to listen if your speech is due to advancement. What does your business obtain that would drive their business enterprise one step further? Exactly what do you might have on their behalf that will make sure they are stand out? You may existing a percentage cut through product sales profits, if your item or even support isn't practical or popular or even associated in any way, they'd the majority of likely change a person lower.
To avoid the poor business enterprise proposal, focus on your own company partners. Give them exactly what they are in search of at a smaller trade as well as let them begin to see the win-win situation with the provide on the table. An example is actually Paypal, that gave Facebook the actual financial support it necessary as a commence up in return for a smaller inventory proportion, and became component of an incredibly prosperous enterprise.
Partnership marketing and advertising tactics making use of associations like a power source entails three points: knowing, deciding on, as well as concentrating. Know which associations would offer you additional worth, select them, and concentrate in it.
Chemistry Scientific Reasons 2nd year 2010
Chemistry Scientific Reasons 2010
Give the scientific reasons of the following: (Answers in the end.)
1. Transition elements form complex compounds.
2. Nitric acid is a strong oxidizing agent.
3. Na+ ion is smaller than Na atom.
4. Sulphuric acid has higher boiling point and viscosity.
5. 4s orbital is filled prior to 3d but on ionization the 4s electrons are lost first.
6. Anhydrous CuSO4 is white while hydrous CuSO4 is blue.
7. The heat of hydration of Li+ ion is greater than Cs+ ion.
8. Diamond does not conduct electricity while graphite does.
9. Nascent hydrogen is more reactive than ordinary molecular hydrogen.
10. Elements of group IA and group IIA readily loses their valence electrons.
11. Transition elements are paramagnetic.
12. Melting and boiling point of IA group elements are very low.
13. Ligands are generally called Lewis base.
14. Bromine is displaced from its salts by chlorine.
15. (NH4)+ and H3O+ ions donot act as ligands though H2O and NH3 act as ligands.
16. The salts of alkaline earth metals are hydrated than alkali metal salts.
17. Zn(OH)2 is soluble in excess of NaOH solution.
18. Why do chromium (24) and copper (29) shows an electronic configuration which is out of order.
19. Assign reasons for formation of coloured ion in case of transition elements except zinc.
20. Ionization enthalpies of IIA group elements are higher than IA group elements.
21. Graphite is used as Lubricant.
22. Metallic character of Aluminium is greater than Boron.
23. Plastic sulphur is elastic.
24. Alkaline earth metals are harder than alkali metals.
25. Ordinary hydrogen called as molecular hydrogen.
26. Electropositively increases from top to bottom.
27. Transition elements show variable oxidation state.
28. Na+ ions are discharged at the cathode in preference to H+ in the manufacture NaOH in Castner Kelner cell.
29. Li+/Li couple has exceptionally high negative electrode potential.
Answers to Scientific Reasons
1.
Transition elements have small highly charged ions and vacant d-orbitals of suitable energy. These vacant d-orbitals form coordinate bond by accepting lone electron pairs from ligands. This is the reason why transition elements form coordination compounds.
2.
The oxidizing properties of nitric acid is due to the stability of its molecule and because nitrogen is present in its highest oxidation state, i.e. 5. The degree of oxidation depends upon the concentration of acid and nature of element.
3.
The number of protons in Na+ ion are greater than the number of electrons due to which the nuclear attraction increases. And Na+ has one shell less than Na atom, because the last shell consists of only one electron, which is not present in Na+ ion. These are the reason due to which Na+ ion has smaller radii than Na atom.
4.
Sulphuric acid has higher boiling point and viscosity due to the presence of hydrogen bonding which link the molecules in larger aggregates.
5.
According to Aufbau principle and n+l rule, the sequence of filling in atomic orbitals in dependent on the value of n + l.
Since,
n + l for 4s = 4 + 0 = 4
and,
n + l for 3d = 3 + 2 = 5s
Therefore, electron goes in the orbital having lowest energy i.e. 4s. In the same way, the electron in 4s orbital have less energy, therefore they are lost first during ionization.
6.
Hydrated CuSO4.5H2O contains 5 molecules of water of crystallization and water act as ligand. The lone pair of electron of water molecules influence the 3d orbital of Cu by splitting it into eg and t2g. Thus by absorbing visible light an electron can jump from lower energy set (t2g) to higher energy set (eg). In doing so some of the component wavelength of light is removed, so the remaining component wavelength of light reflected shows the blue colour. An hydrous CuSO4 is colourless due to the absence of water molecule.
7.
The atomic size of Lithium is much smaller than that of Cesium, therefore its charge density is more. Due to more charge density, the electrons are attracted with a greater force of attraction. This is the reason more amount of heat is liberated when one mole of Li+ ion is dissolved in water. This is the reason why heat of hydration decreases down the group.
8.
In diamond, each carbon atom is sp3 hyberidized and is strongly bonded to four other carbon atoms. It utilizes its four unpaired electrons in the formation of four covalent bonds. Since, it has no free electrons; it is a poor conductor of electricity.
Whereas, in graphite, each carbon is sp2 hybridized and covalently linked with three other carbon atoms to give basic hexagonal ring. These hexagonal rings are 3.35 A° away from each other and are held together by weak Vander Waal’s forces. The fourth electron of each carbon forms delocalized p bonds, which are spread uniformly. This is the reason graphite conducts electricity.
9.
Molecular hydrogen is composed of two atoms of hydrogen. They are held together by a covalent bond. The bond energy of this covalent bond is 104 kcal/mole. In order to be reactive, the molecular hydrogen needs an energy to over come the bonding energy i.e. greater than 104 kcal /mole. Whereas in case of atomic hydrogen no such condition is required. This is the reason why atomic hydrogen is more reactive.
10.
The elements in group IA and and IIA have only one or two electron in their valence shell. As we move from right to left in the periodic table, the nuclear charge decreases, which increases the atomic size and reduces the force on valence electron. This is the reason why elements of group IA and IIA readily lose their electrons.
11.
The paramagnetic property of an element depends upon the availability of free electrons. Many compounds of the transition elements are paramagnetic. This is because they have unpaired electrons in their d-orbitals, which becomes active in a magnetic field.
12.
The elements of group IA have large atomic radii and small nuclear charges. This is the reason why melting point, boiling points are lower than other elements in the periods.
13.
Ligands are atoms, molecules or ions that donate a lone pair of electron to metal and form coordinate bond with them. According to Lewis, bases are substances that donate a lone pair of electrons. This is the reason why ligands are called Lewis base.
14.
The electronegativity of chlorine is greater than that of bromine. Because it decreases down the group. Since, chlorine is more electronegative than bromine, it displaces bromine from its salts.
15.
In case of NH3, the central atom nitrogen contains a lone pair of electron, which it can donate to metal. Whereas incase of NH4+, the central atom nitragen has already donated its lone pair to hydrogen so it does not act as ligand. Similarly H2O act as ligand but H3O+ does not act as ligand.
16.
Hydration of cations depend upon the nuclear charge and ionic radii. Smaller the ionic radii, greater would be the nuclear charge and more the salt will show the tendency for hydration. Since, the alkali earth metals have a greater nuclear charge and a stronger electric field than the alkali metals, therefore, they are more hydrated than alkali salts.
17.
Zinc hydroxide I an emphotric substance, i.e. it shows both acidic and basic properties. Therefore, when Zn(OH)2 is dissolved in excess of NaOH solution it does not precipitate out but forms a complex ion and redissolves.
Zn(OH)2 + 2NaOH ® [Zn(OH)4]-2 + 2Na+
Tetra Hydroxozincate
18.
24Cr = 4s23d4 ® (4s13d5)
29Cu = 4s23d9 ® (4s13d10)
The half filled or completely filled orbitals are more stable than other wise filled orbitals. In case of Cromium the one electron of 4s orbital jumps into 3d orbital, as a result 4s and 3d orbitals are half filled and stabized. Similarly in copper one electron of 4s orbital jumps into 3d orbital, as a result 4s is half filled whereas 3d is completely filled.
Hence electronic configuration of Cromium (Cr) is 4s13d5 instead of 4s23d4 and configuration of copper (Cu) is 4s13d10 instead of 4s23d9.
19.
The formation of coloured ion in case of transition elements can be explained by Crystal Field Theory. According to the theory (C.F.T) the bonding between ligand and a metal ion is electrostatic. The ligands surrounding the metal ion create an electrostatic field around its d-orbital. This field splits five degenerated d-orbitals into two sets with different energies.
The energy difference between two sets (eg and t2g) of d orbital is equivalent to a wavelength in a visible region. Thus by absorbing visible light, an electron may be able to move from lower energy set (t2g) to higher energy set eg of d orbitals. In doing so some of the component wavelength of white light is removed, so the remaining component wavelength of light reflected or transmitted shows the colour of ion.
Hence the colour of the ion is due to the half filled 3d orbital, the electron can jump from d orbital of lower energy by the absorption of small amount of energy of a particular wavelength in a visible region. Since in case of zinc, the 3d orbital is completely filled therefore the compounds of Zinc are white or colourless.
20.
The ionization enthalpies IIA (alkaline earth elements) is higher than the corresponding ionization enthalpies of IA group (alkali metals0, because elements of IIA group has an extra nuclear proton which causes an increase in the electrostatic Beautiful force between the nucleus and the outer most electron.
21.
In Graphite, each carbon is Sp2 hyberidized and covalently linked with three other carbon atoms to give basic hexagonal ring. These hexagonal rings then form layers in graphite. These layers are 3.35 A° away from one another and held together by weak Vander Waal’s forces of attraction. Due to large inter planner distance (3.35A°), the layers slide easily over one another that is why it is soft and used as Lubricant.
22.
The maximum capacity of electron accomodation of boron in its outer most shell is eight electrons and that of Aluminium is eighteen electron.
5B = 1s2, 2s2, 2p1
13Al = 1s2, 2s2, 2p6, 3s2, 3p1
It means electron population of aluminium is less than boron. Due to less electron population, the number of neighbouring atoms in the lattice increases, that is why metallic character of aluminium is greater than boron.
23.
The plastic sulphur or g-sulphur is composed of long chains of sulphur atoms. The elasticity of plastic sulphur is due to uncoiling of long sulphur chains and then recoiling of chains by the release of tension.
24.
The alkaline earth metals (II group metals) are appreciably harder than alkali metals (I group) because the presence of divalent cations in their metallic structure produce greater bonding forces.
25.
Ordinary hydrogen exist as diatomic molecule (H2) therefore it is also known as molecular hydrogen.
26.
The tendency of atom to give out electrons is known as electropositivity. Electropositivity is inversely proportional to ionization potential and electron population. Both the factors decreases down the group, hence electropositivity increases from top to bottom.
27.
The transition elemenets show variable oxidation states in their compounds. This variation is due to the very small energy difference in between 3d and 4s orbitals. As a result, electrons of 3d as well as 4s takes part in the bond formation.
28.
In castner-kellner cell, H+ ions are not easily discharged due to high voltage of H+ ion, on the contrary Na+ ions are easily discharged over mercury surface.
29.
Li+/Li couple has exceptionally high negative electrode potential because of its large value for the hydration enthalpy which promotes oxidation of Li to form Li+ ion.
Give the scientific reasons of the following: (Answers in the end.)
1. Transition elements form complex compounds.
2. Nitric acid is a strong oxidizing agent.
3. Na+ ion is smaller than Na atom.
4. Sulphuric acid has higher boiling point and viscosity.
5. 4s orbital is filled prior to 3d but on ionization the 4s electrons are lost first.
6. Anhydrous CuSO4 is white while hydrous CuSO4 is blue.
7. The heat of hydration of Li+ ion is greater than Cs+ ion.
8. Diamond does not conduct electricity while graphite does.
9. Nascent hydrogen is more reactive than ordinary molecular hydrogen.
10. Elements of group IA and group IIA readily loses their valence electrons.
11. Transition elements are paramagnetic.
12. Melting and boiling point of IA group elements are very low.
13. Ligands are generally called Lewis base.
14. Bromine is displaced from its salts by chlorine.
15. (NH4)+ and H3O+ ions donot act as ligands though H2O and NH3 act as ligands.
16. The salts of alkaline earth metals are hydrated than alkali metal salts.
17. Zn(OH)2 is soluble in excess of NaOH solution.
18. Why do chromium (24) and copper (29) shows an electronic configuration which is out of order.
19. Assign reasons for formation of coloured ion in case of transition elements except zinc.
20. Ionization enthalpies of IIA group elements are higher than IA group elements.
21. Graphite is used as Lubricant.
22. Metallic character of Aluminium is greater than Boron.
23. Plastic sulphur is elastic.
24. Alkaline earth metals are harder than alkali metals.
25. Ordinary hydrogen called as molecular hydrogen.
26. Electropositively increases from top to bottom.
27. Transition elements show variable oxidation state.
28. Na+ ions are discharged at the cathode in preference to H+ in the manufacture NaOH in Castner Kelner cell.
29. Li+/Li couple has exceptionally high negative electrode potential.
Answers to Scientific Reasons
1.
Transition elements have small highly charged ions and vacant d-orbitals of suitable energy. These vacant d-orbitals form coordinate bond by accepting lone electron pairs from ligands. This is the reason why transition elements form coordination compounds.
2.
The oxidizing properties of nitric acid is due to the stability of its molecule and because nitrogen is present in its highest oxidation state, i.e. 5. The degree of oxidation depends upon the concentration of acid and nature of element.
3.
The number of protons in Na+ ion are greater than the number of electrons due to which the nuclear attraction increases. And Na+ has one shell less than Na atom, because the last shell consists of only one electron, which is not present in Na+ ion. These are the reason due to which Na+ ion has smaller radii than Na atom.
4.
Sulphuric acid has higher boiling point and viscosity due to the presence of hydrogen bonding which link the molecules in larger aggregates.
5.
According to Aufbau principle and n+l rule, the sequence of filling in atomic orbitals in dependent on the value of n + l.
Since,
n + l for 4s = 4 + 0 = 4
and,
n + l for 3d = 3 + 2 = 5s
Therefore, electron goes in the orbital having lowest energy i.e. 4s. In the same way, the electron in 4s orbital have less energy, therefore they are lost first during ionization.
6.
Hydrated CuSO4.5H2O contains 5 molecules of water of crystallization and water act as ligand. The lone pair of electron of water molecules influence the 3d orbital of Cu by splitting it into eg and t2g. Thus by absorbing visible light an electron can jump from lower energy set (t2g) to higher energy set (eg). In doing so some of the component wavelength of light is removed, so the remaining component wavelength of light reflected shows the blue colour. An hydrous CuSO4 is colourless due to the absence of water molecule.
7.
The atomic size of Lithium is much smaller than that of Cesium, therefore its charge density is more. Due to more charge density, the electrons are attracted with a greater force of attraction. This is the reason more amount of heat is liberated when one mole of Li+ ion is dissolved in water. This is the reason why heat of hydration decreases down the group.
8.
In diamond, each carbon atom is sp3 hyberidized and is strongly bonded to four other carbon atoms. It utilizes its four unpaired electrons in the formation of four covalent bonds. Since, it has no free electrons; it is a poor conductor of electricity.
Whereas, in graphite, each carbon is sp2 hybridized and covalently linked with three other carbon atoms to give basic hexagonal ring. These hexagonal rings are 3.35 A° away from each other and are held together by weak Vander Waal’s forces. The fourth electron of each carbon forms delocalized p bonds, which are spread uniformly. This is the reason graphite conducts electricity.
9.
Molecular hydrogen is composed of two atoms of hydrogen. They are held together by a covalent bond. The bond energy of this covalent bond is 104 kcal/mole. In order to be reactive, the molecular hydrogen needs an energy to over come the bonding energy i.e. greater than 104 kcal /mole. Whereas in case of atomic hydrogen no such condition is required. This is the reason why atomic hydrogen is more reactive.
10.
The elements in group IA and and IIA have only one or two electron in their valence shell. As we move from right to left in the periodic table, the nuclear charge decreases, which increases the atomic size and reduces the force on valence electron. This is the reason why elements of group IA and IIA readily lose their electrons.
11.
The paramagnetic property of an element depends upon the availability of free electrons. Many compounds of the transition elements are paramagnetic. This is because they have unpaired electrons in their d-orbitals, which becomes active in a magnetic field.
12.
The elements of group IA have large atomic radii and small nuclear charges. This is the reason why melting point, boiling points are lower than other elements in the periods.
13.
Ligands are atoms, molecules or ions that donate a lone pair of electron to metal and form coordinate bond with them. According to Lewis, bases are substances that donate a lone pair of electrons. This is the reason why ligands are called Lewis base.
14.
The electronegativity of chlorine is greater than that of bromine. Because it decreases down the group. Since, chlorine is more electronegative than bromine, it displaces bromine from its salts.
15.
In case of NH3, the central atom nitrogen contains a lone pair of electron, which it can donate to metal. Whereas incase of NH4+, the central atom nitragen has already donated its lone pair to hydrogen so it does not act as ligand. Similarly H2O act as ligand but H3O+ does not act as ligand.
16.
Hydration of cations depend upon the nuclear charge and ionic radii. Smaller the ionic radii, greater would be the nuclear charge and more the salt will show the tendency for hydration. Since, the alkali earth metals have a greater nuclear charge and a stronger electric field than the alkali metals, therefore, they are more hydrated than alkali salts.
17.
Zinc hydroxide I an emphotric substance, i.e. it shows both acidic and basic properties. Therefore, when Zn(OH)2 is dissolved in excess of NaOH solution it does not precipitate out but forms a complex ion and redissolves.
Zn(OH)2 + 2NaOH ® [Zn(OH)4]-2 + 2Na+
Tetra Hydroxozincate
18.
24Cr = 4s23d4 ® (4s13d5)
29Cu = 4s23d9 ® (4s13d10)
The half filled or completely filled orbitals are more stable than other wise filled orbitals. In case of Cromium the one electron of 4s orbital jumps into 3d orbital, as a result 4s and 3d orbitals are half filled and stabized. Similarly in copper one electron of 4s orbital jumps into 3d orbital, as a result 4s is half filled whereas 3d is completely filled.
Hence electronic configuration of Cromium (Cr) is 4s13d5 instead of 4s23d4 and configuration of copper (Cu) is 4s13d10 instead of 4s23d9.
19.
The formation of coloured ion in case of transition elements can be explained by Crystal Field Theory. According to the theory (C.F.T) the bonding between ligand and a metal ion is electrostatic. The ligands surrounding the metal ion create an electrostatic field around its d-orbital. This field splits five degenerated d-orbitals into two sets with different energies.
The energy difference between two sets (eg and t2g) of d orbital is equivalent to a wavelength in a visible region. Thus by absorbing visible light, an electron may be able to move from lower energy set (t2g) to higher energy set eg of d orbitals. In doing so some of the component wavelength of white light is removed, so the remaining component wavelength of light reflected or transmitted shows the colour of ion.
Hence the colour of the ion is due to the half filled 3d orbital, the electron can jump from d orbital of lower energy by the absorption of small amount of energy of a particular wavelength in a visible region. Since in case of zinc, the 3d orbital is completely filled therefore the compounds of Zinc are white or colourless.
20.
The ionization enthalpies IIA (alkaline earth elements) is higher than the corresponding ionization enthalpies of IA group (alkali metals0, because elements of IIA group has an extra nuclear proton which causes an increase in the electrostatic Beautiful force between the nucleus and the outer most electron.
21.
In Graphite, each carbon is Sp2 hyberidized and covalently linked with three other carbon atoms to give basic hexagonal ring. These hexagonal rings then form layers in graphite. These layers are 3.35 A° away from one another and held together by weak Vander Waal’s forces of attraction. Due to large inter planner distance (3.35A°), the layers slide easily over one another that is why it is soft and used as Lubricant.
22.
The maximum capacity of electron accomodation of boron in its outer most shell is eight electrons and that of Aluminium is eighteen electron.
5B = 1s2, 2s2, 2p1
13Al = 1s2, 2s2, 2p6, 3s2, 3p1
It means electron population of aluminium is less than boron. Due to less electron population, the number of neighbouring atoms in the lattice increases, that is why metallic character of aluminium is greater than boron.
23.
The plastic sulphur or g-sulphur is composed of long chains of sulphur atoms. The elasticity of plastic sulphur is due to uncoiling of long sulphur chains and then recoiling of chains by the release of tension.
24.
The alkaline earth metals (II group metals) are appreciably harder than alkali metals (I group) because the presence of divalent cations in their metallic structure produce greater bonding forces.
25.
Ordinary hydrogen exist as diatomic molecule (H2) therefore it is also known as molecular hydrogen.
26.
The tendency of atom to give out electrons is known as electropositivity. Electropositivity is inversely proportional to ionization potential and electron population. Both the factors decreases down the group, hence electropositivity increases from top to bottom.
27.
The transition elemenets show variable oxidation states in their compounds. This variation is due to the very small energy difference in between 3d and 4s orbitals. As a result, electrons of 3d as well as 4s takes part in the bond formation.
28.
In castner-kellner cell, H+ ions are not easily discharged due to high voltage of H+ ion, on the contrary Na+ ions are easily discharged over mercury surface.
29.
Li+/Li couple has exceptionally high negative electrode potential because of its large value for the hydration enthalpy which promotes oxidation of Li to form Li+ ion.
Chemistry MCQs
2nd year
Five Year Papers
1. On passing steam over red-hot coal we get __________.
(Water gas, Ethane, Carbonmonoxide)
2. ‘d’ and ‘f’ block elements are called __________.
(Heavy metals, Rare elements, Transition elements)
3. The correct formula of pyrosulphuric acid is __________.
(H2SO4, H2S2O7, H3S2O5)
4. Aqua regia is mixture of one part of __________ by volume and three parts of __________.
(H2SO4, H3PO4, HNO3, HCl)
5. Heavy hydrogen is also called __________.
(Proteum, Deuterium, Hydronium)
6. When boric acid (H3BO3) is heated of 140°C, it forms __________.
(Boric Acid, Pyroboric acid, Metaboric acid)
7. Photographic film is made of sheets of __________.
(Cellulose Acetate, P.V.A, Nylon)
8. C4H8 is a saturated hydrocarbon because it is __________.
(Cyclic, Open chain, Polymer)
9. n-Octane is __________ at room temperature.
(Gas, Liquid, Semi-solid)
10. The compound formed between an element A of group IIIA and an element B of group VIA has the formula __________.
(AB, A2, B3, A2B3)
11. The oxide formed by AI is __________.
(Acidic, Amphoteric, Basic)
12. Bakelite is a polymer of __________ and form aldehyde.
(Ethane, Methanol, Phenol)
13. The plastics, which can be heated only once, are known as __________ plastics.
(Perspex, Thermoplastic, Thermosetting)
14. The deficiency of __________ in the human body is the cause of diabetes.
(Insulin, Alamin, Ptyalin)
15. If the level of cholesterol increases in the blood serum, it causes __________.
(Diabetes,Heart attact, High blood pressure)
16. The formula of baking soda is __________.
(NaHCO3, Na2CO3, Na2CO310H2O)
17. The formula of Plaster of Paris is __________.
(CaSO4.2H2O, 2CaSO4.H2O, (CaSO4)2H2O)
18. The atoms of the elements belonging to the same period of the Periodic table have __________.
(Same number of protons, same number of neutrons, same number of valence shells)
19. Sodium thiosulphate is used in photography because of its __________.
(Reducing power, Complex formation, Oxidizing behaviour)
20. The outer electronic configuration of copper is __________.
(4s14d10, 4s23d10, 4s13d10)
21. H2S solution in water is __________.
(Neutral, Acidic, Basic)
22. __________ is isomer of ethanol.
(CH3OH, CH3OCH3, C6H5OH)
23. Petroleum is a mixture of __________.
(Alkanes and alkenes, aromatic hydrocarbons, all of these)
24. Glucose is __________.
(Reducing sugar, oxidizing sugar, none of these)
25. Pentane shows __________.
(Two isomers, three isomers, four isomers)
Chapter 1
Periodic Classification of Elements
1. __________ elements have been discovered so far.
(100, 110, 120, 150)
2. so far 110 elements have been discovered. Out of these __________ elements are naturally occurring.
(100, 96, 92, 94)
3. __________ classified the then known elements into metals, non metals and their derivatives.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
4. In 1817, a German chemist, __________ made use of the idea of relationship between atomic weights and properties of elements for the classification of elements.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
5. __________ presented the law of triads.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
6. Dobreiner’s work led to the law of triads which states that __________.
(Atomic weight of any one lement was found to be approximately the mean of the other two elements of triad, Atomic weight of the middle element was found to be approximately the mean of the other two elements of a triad, Atomic number of any one element was found to be approximately the mean of the other two elements of a triad, Atomic number of the middle element was found to be approximately the mean of the other two elements of triad)
7. The law of octaves was given by __________.
(Dobreiner, Al- Razi, Newlands, None of these)
8. Law of octaves states that __________.
(The properties of every 6th element from the given one were similar to the first, the properties of every 9th element from the given one were similar to the first, the properties of every 8th element from the given one were similar to the first, the properties of every 7th element from the given one were similar to the second)
9. “Physical and chemical properties of elements are periodic functions of their atomic weight.” This is called __________.
(Dobereiner’s Law of Triads, Newlands’ Law of Octaves, Mendeleev’s Periodic Law, None of these)
10. Lother Meyer arranged the elements in order of their increasing atomic weights and found that __________.
(Physical propertis of the elements were the periodic function of their atomic weights, chemical properties of the elements were the periodic function of their atomic number, physical properties of the elements were the periodic function of their atomic number, chemical properties of the elements were periodic function of their atomic weights)
11. Mendeleev’s Periodic table was based on __________.
(Atomic number, Atomic mass, Atomic volume, Electronic Configuration)
12. Mandeleev formulated a rule for the classification of elements and concluded that __________.
(Physical and chemical properties of the elements are periodic functions of their atomic numbers, physical and chemical properties of the elements are periodic functions of their atomic weights, physical properties of the elements are periodic function of their atomic weights, Chemical properties of the elements are periodic functions of their atomic numbers)
13. Modern Classification of elements is based on __________.
(Doberiner’s law of Triads, Newlands’ law of Octaves, Mendeleev’s Periodic Table, None of these)
14. Excluding H and He, the smallest element in the periodic table is __________.
(Lithium, Fluorine, Cesium, Iodine)
15. “Physical and chemical properties of elements are the periodic functions of their atomic numbers.” This is called __________.
(Law of Triads, Law of Octaves, Periodic Law, None of these)
16. Moseley’s work led to the periodic law, which states that __________.
(the number of the electrons in the 1s energy level increases as the atomic number increases, The properties of the elements are a periodic function of their atomic masses, The x-rays spectra of the elements are more complex than the optical spectra, The properties of elements are the periodic function of their atomic number)
17. A pair of elements in the same family in the periodic table classification is __________.
(Chlorine and carbon, calcium and aluminium, nitrogen and neon, sodium and potassium)
18. In the period, the elements are arranged in strict sequence in order of __________.
(Increasing charges in the nucleus, increasing atomic weight, increasing number of electrons in valence shell, increasing valency)
19. Most of the known elements are metals of __________ of periodic table.
(d-block, p-block, III-group, Zero block)
20. __________ reflects combining capacity of an element.
(Valency, atomic number, ionization energy, ionization potential)
21. As we move from left to right in second period of the periodic table, the gram atomic volume of the elements __________.
(Increases at a constant rate, remains unchanged, decreases, will change indefinitely)
22. The volume in cubic centimeters occupied by one gram atom of the element is called __________.
(Atomic Volume, Atomic weight, Mass number, None of these)
23. In a __________, atomic volume increases with atomic number, from top to bottom, as new shells are added up with increase in atomic number.
(Group, Period, Sub-group, None of these)
24. __________ of the following is a transition element.
(Ni, Rb, Al, As)
25. On moving from left to right across a period in the periodic table, the size of atom generally __________.
(decreases, increases, remains constant, decreases up to IV A group and then increases)
26. The amount of energy required to remove an electron from an atom of an element in the gaseous state I called __________.
(Ionization Potential, Ionization energy, Electron volt, both a and b)
27. Each vertical row of the periodic table includes elements with chemical characteristics that are in general __________.
(identical, similar, different, sometimes identical and sometimes differents)
28. The ionization energy __________ in a group from top to bottom with the increase in atomic size.
(Increases, decreases, remains constant, none of these)
29. The lowest ionization energies are found in the __________.
(inert gases, alkali metals, Transition elements, Halogens)
30. Ionization energy is lowest for __________.
(Inert gases, alkali metals, halogens, alkaline earth metals)
31. In the periodic table, the highest ionization energies are for __________.
(Halogens, Noble gases, Alkali metals, Chalcogens)
32. The atomic weight of an element divided by its density is called __________.
(Atomic mass, Atomic volume, Atomic density, Atomic number)
33. Elements in the same family __________.
(have same atomic number, have the same molecular weight, have similar chemical properties, constitute a group of elements with the same electronic configuration)
34. In a given period, the alkali metals have __________.
(smallest atomic size, lowest ionization energy, lowest density, highest electron affinity)
35. Of the following given elements __________ atom has the highest ionization energy.
(Be, F, N, Ne)
36. The value of ionization energy __________ in a period from left to right due to the decrease in atomic size.
(increases, decreases, remains constant, None of these)
37. __________ is the most electronegative element.
(Fluorine, Iodine, Oxygen, Sodium)
38. The unit of ionization energy is __________.
(Joule, Calorie, electron volt, none of these)
39. Of the following elements, __________ element has the highest first ionization potential.
(Boron, carbon, nitrogen, oxygen)
40. The unit of ionization potential is __________.
(Joule, joule per mole, calorie per mole, none of these)
41. In a period, the ensity of normal elements first __________ and then __________ after reaching a maximum value somewhere in the middle.
(Increases, decreases, remains constant, none of these)
42. Most of the known elements are __________.
(Rrystalloids, Metals, Metalloids, Non metals)
Five Year Papers
1. On passing steam over red-hot coal we get __________.
(Water gas, Ethane, Carbonmonoxide)
2. ‘d’ and ‘f’ block elements are called __________.
(Heavy metals, Rare elements, Transition elements)
3. The correct formula of pyrosulphuric acid is __________.
(H2SO4, H2S2O7, H3S2O5)
4. Aqua regia is mixture of one part of __________ by volume and three parts of __________.
(H2SO4, H3PO4, HNO3, HCl)
5. Heavy hydrogen is also called __________.
(Proteum, Deuterium, Hydronium)
6. When boric acid (H3BO3) is heated of 140°C, it forms __________.
(Boric Acid, Pyroboric acid, Metaboric acid)
7. Photographic film is made of sheets of __________.
(Cellulose Acetate, P.V.A, Nylon)
8. C4H8 is a saturated hydrocarbon because it is __________.
(Cyclic, Open chain, Polymer)
9. n-Octane is __________ at room temperature.
(Gas, Liquid, Semi-solid)
10. The compound formed between an element A of group IIIA and an element B of group VIA has the formula __________.
(AB, A2, B3, A2B3)
11. The oxide formed by AI is __________.
(Acidic, Amphoteric, Basic)
12. Bakelite is a polymer of __________ and form aldehyde.
(Ethane, Methanol, Phenol)
13. The plastics, which can be heated only once, are known as __________ plastics.
(Perspex, Thermoplastic, Thermosetting)
14. The deficiency of __________ in the human body is the cause of diabetes.
(Insulin, Alamin, Ptyalin)
15. If the level of cholesterol increases in the blood serum, it causes __________.
(Diabetes,Heart attact, High blood pressure)
16. The formula of baking soda is __________.
(NaHCO3, Na2CO3, Na2CO310H2O)
17. The formula of Plaster of Paris is __________.
(CaSO4.2H2O, 2CaSO4.H2O, (CaSO4)2H2O)
18. The atoms of the elements belonging to the same period of the Periodic table have __________.
(Same number of protons, same number of neutrons, same number of valence shells)
19. Sodium thiosulphate is used in photography because of its __________.
(Reducing power, Complex formation, Oxidizing behaviour)
20. The outer electronic configuration of copper is __________.
(4s14d10, 4s23d10, 4s13d10)
21. H2S solution in water is __________.
(Neutral, Acidic, Basic)
22. __________ is isomer of ethanol.
(CH3OH, CH3OCH3, C6H5OH)
23. Petroleum is a mixture of __________.
(Alkanes and alkenes, aromatic hydrocarbons, all of these)
24. Glucose is __________.
(Reducing sugar, oxidizing sugar, none of these)
25. Pentane shows __________.
(Two isomers, three isomers, four isomers)
Chapter 1
Periodic Classification of Elements
1. __________ elements have been discovered so far.
(100, 110, 120, 150)
2. so far 110 elements have been discovered. Out of these __________ elements are naturally occurring.
(100, 96, 92, 94)
3. __________ classified the then known elements into metals, non metals and their derivatives.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
4. In 1817, a German chemist, __________ made use of the idea of relationship between atomic weights and properties of elements for the classification of elements.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
5. __________ presented the law of triads.
(Dobreiner, Al-Razi, Newlands, Mendeleeve)
6. Dobreiner’s work led to the law of triads which states that __________.
(Atomic weight of any one lement was found to be approximately the mean of the other two elements of triad, Atomic weight of the middle element was found to be approximately the mean of the other two elements of a triad, Atomic number of any one element was found to be approximately the mean of the other two elements of a triad, Atomic number of the middle element was found to be approximately the mean of the other two elements of triad)
7. The law of octaves was given by __________.
(Dobreiner, Al- Razi, Newlands, None of these)
8. Law of octaves states that __________.
(The properties of every 6th element from the given one were similar to the first, the properties of every 9th element from the given one were similar to the first, the properties of every 8th element from the given one were similar to the first, the properties of every 7th element from the given one were similar to the second)
9. “Physical and chemical properties of elements are periodic functions of their atomic weight.” This is called __________.
(Dobereiner’s Law of Triads, Newlands’ Law of Octaves, Mendeleev’s Periodic Law, None of these)
10. Lother Meyer arranged the elements in order of their increasing atomic weights and found that __________.
(Physical propertis of the elements were the periodic function of their atomic weights, chemical properties of the elements were the periodic function of their atomic number, physical properties of the elements were the periodic function of their atomic number, chemical properties of the elements were periodic function of their atomic weights)
11. Mendeleev’s Periodic table was based on __________.
(Atomic number, Atomic mass, Atomic volume, Electronic Configuration)
12. Mandeleev formulated a rule for the classification of elements and concluded that __________.
(Physical and chemical properties of the elements are periodic functions of their atomic numbers, physical and chemical properties of the elements are periodic functions of their atomic weights, physical properties of the elements are periodic function of their atomic weights, Chemical properties of the elements are periodic functions of their atomic numbers)
13. Modern Classification of elements is based on __________.
(Doberiner’s law of Triads, Newlands’ law of Octaves, Mendeleev’s Periodic Table, None of these)
14. Excluding H and He, the smallest element in the periodic table is __________.
(Lithium, Fluorine, Cesium, Iodine)
15. “Physical and chemical properties of elements are the periodic functions of their atomic numbers.” This is called __________.
(Law of Triads, Law of Octaves, Periodic Law, None of these)
16. Moseley’s work led to the periodic law, which states that __________.
(the number of the electrons in the 1s energy level increases as the atomic number increases, The properties of the elements are a periodic function of their atomic masses, The x-rays spectra of the elements are more complex than the optical spectra, The properties of elements are the periodic function of their atomic number)
17. A pair of elements in the same family in the periodic table classification is __________.
(Chlorine and carbon, calcium and aluminium, nitrogen and neon, sodium and potassium)
18. In the period, the elements are arranged in strict sequence in order of __________.
(Increasing charges in the nucleus, increasing atomic weight, increasing number of electrons in valence shell, increasing valency)
19. Most of the known elements are metals of __________ of periodic table.
(d-block, p-block, III-group, Zero block)
20. __________ reflects combining capacity of an element.
(Valency, atomic number, ionization energy, ionization potential)
21. As we move from left to right in second period of the periodic table, the gram atomic volume of the elements __________.
(Increases at a constant rate, remains unchanged, decreases, will change indefinitely)
22. The volume in cubic centimeters occupied by one gram atom of the element is called __________.
(Atomic Volume, Atomic weight, Mass number, None of these)
23. In a __________, atomic volume increases with atomic number, from top to bottom, as new shells are added up with increase in atomic number.
(Group, Period, Sub-group, None of these)
24. __________ of the following is a transition element.
(Ni, Rb, Al, As)
25. On moving from left to right across a period in the periodic table, the size of atom generally __________.
(decreases, increases, remains constant, decreases up to IV A group and then increases)
26. The amount of energy required to remove an electron from an atom of an element in the gaseous state I called __________.
(Ionization Potential, Ionization energy, Electron volt, both a and b)
27. Each vertical row of the periodic table includes elements with chemical characteristics that are in general __________.
(identical, similar, different, sometimes identical and sometimes differents)
28. The ionization energy __________ in a group from top to bottom with the increase in atomic size.
(Increases, decreases, remains constant, none of these)
29. The lowest ionization energies are found in the __________.
(inert gases, alkali metals, Transition elements, Halogens)
30. Ionization energy is lowest for __________.
(Inert gases, alkali metals, halogens, alkaline earth metals)
31. In the periodic table, the highest ionization energies are for __________.
(Halogens, Noble gases, Alkali metals, Chalcogens)
32. The atomic weight of an element divided by its density is called __________.
(Atomic mass, Atomic volume, Atomic density, Atomic number)
33. Elements in the same family __________.
(have same atomic number, have the same molecular weight, have similar chemical properties, constitute a group of elements with the same electronic configuration)
34. In a given period, the alkali metals have __________.
(smallest atomic size, lowest ionization energy, lowest density, highest electron affinity)
35. Of the following given elements __________ atom has the highest ionization energy.
(Be, F, N, Ne)
36. The value of ionization energy __________ in a period from left to right due to the decrease in atomic size.
(increases, decreases, remains constant, None of these)
37. __________ is the most electronegative element.
(Fluorine, Iodine, Oxygen, Sodium)
38. The unit of ionization energy is __________.
(Joule, Calorie, electron volt, none of these)
39. Of the following elements, __________ element has the highest first ionization potential.
(Boron, carbon, nitrogen, oxygen)
40. The unit of ionization potential is __________.
(Joule, joule per mole, calorie per mole, none of these)
41. In a period, the ensity of normal elements first __________ and then __________ after reaching a maximum value somewhere in the middle.
(Increases, decreases, remains constant, none of these)
42. Most of the known elements are __________.
(Rrystalloids, Metals, Metalloids, Non metals)
43. Melting and boiling points gradually __________ in a
periodic table from left to right up to the middle.
(increases, decreases, remains constnt, none of these)
44. The electropositive elements form __________.
(acidic oxides, basic oxides, neutral oxides, none of these)
45. __________ of the following elements has the lowest first ionization energy.
(Na, F, I, Cs)
46. The electronegative elements form __________.
(Acidic oxides, Basic oxides, Neutral oxides, none of these)
47. __________ is the most volatile compound.
(HI, HCl, HBr, HF)
48. The ionization energy of nitrogen is more than oxygen because of __________.
(more attraction of electrons by the nucleus, more peneration effect, the extra stability of half filled p-orbitals, the size of nitrogen atom is smaller)
49. The elements of group IIA are called __________.
(Metals, Non-metals, Alkaline earth metals, Transition elements)
50. __________ ion has the largest radius.
(Al+3, Cl-, F-, O-2)
51. __________ atom has the smallest size.
(C, F, Li, Rb)
52. __________ of the following has highest first ionization energy.
(Br, Cl, F, I)
53. The most electropositive among the following elements is __________.
(Fe, Na, Cs, Pb)
Chapter 2
Hydrogen
1. Large amounts of atomic hydrogen are present in the atmosphere of __________.
(Earth, Sun, Moon, none of these)
2. Hydrogen atom contains __________ electrons.
(1, 2, 3, 4)
3. During the electrolysis of water hydrogen is liberated at the __________.
(Anode, Cathode, Diode, none of these)
4. The atomic weight of hydrogen is __________.
(1.00, 1.008, 1.08, 1.800)
5. In nature hydrogen exists in __________.
(Gaseous state, Solid state, Liquid state, Plasma state)
6. __________ is the lightest gas.
(Nitrogen, Helium, Oxygen, Hydrogen)
7. Alkali metals do not exist in __________.
(Monoatomic, Diatomic, Triatomic, none of these)
8. Hydrogen generally combines with other elements to form __________.
(Ionic bond, Covalent bond, Polar bond, none of these)
9. Hydrogen may be readily prepared by the action of water on __________.
(Fe, HCl, Zn, Na)
10. In organic compounds, __________ element is found in close association with hydrogen.
(C, N, O, none of these)
11. Ionic hydrides are usually __________.
(liquids at room temperature, good reducing agents, good electrical conductors in solid state, Easily reduced)
12. The atoms of the same element, which have the same atomic number but different mass numbers, are called __________.
(Isotopes, Actanides, Isobars, none of these)
13. The difference in atomic weights or mass numbers of the atoms of the same element is due to __________.
(Different number of electrons in them, different number of protons in them, different number of neutrons in them, none of these)
14. A tritium nucleus has __________.
(one proton and two electrons, one proton and two neutrons, one neutrons and two protons, one proton and three neutrons)
15. Physical properties of elements depend upon the number of __________.
(Protons in the nucleus, neutrons in the nucleus, electrons in the valence shell, both protons and neutrons in the nucleus)
16. Chemical properties of elements depend upon the number of __________.
(electrons in the valence shell, protons in the nucleus, neutrons in the nucleus, protons and neutrons in the nucleus)
17. Chemical properties of elements depend upon their __________.
(Atomic number, Atomic weight, volume, none of these)
18. The hydronium ion is a/an __________.
(ion with formula H2O+, ion with the formula H3O+, free radical rather than an ion, ion formed by removal of H- form a water molecules)
19. Hydrogen is an important constituent of __________.
(Water, Petroleum, Natural gas, all of these)
20. When steam is passed over red hot coke at 1000°C, a mixture of carbon monoxide and hydrogen gas is produced. It is known as __________.
(Heavy water, Water gas, Phosgen gas, none of these)
21. The most suitable process for the separation of CO from water gas is __________.
(Bosch Proces, Lane’s Process, Electrolysis of water, None of these)
22. When steam is passed over iron at 500°C, magnetic oxide and hydrogen gas is produced. This is called __________.
(Bosch Process, Lane’s Process, Electrolysis, All of these)
23. The presence of an acid or base renders water __________.
(good conductor of electricity, poor conductor of electricity, very bad conductor of electricity, all of these)
24. The process of loss of oxygen from a substance or addition of hydrogen is called __________.
(Oxidation, Reduction, Hydrogenation, None of these)
25. Hydrogen is a very good __________.
(Reducing agent, Oxidizing agent, Reducing agent as well as oxidizing agent, none of these)
26. Lowering of oxidation state of a metal is termed s __________.
(Oxidation, Reduction, Hydrogenation, All of these)
27. The process of addition of hydrogen (H2) to a molecule is called __________.
(Oxidation, Reduction, Hydrogenation, all of these)
28. Formation of vegetable ghee from vegetable oil is an example of __________.
(Oxidation, Reduction, Hydrogenation, all of these)
29. Ethylene can be hydrogenated to __________ under pressure at about 300°C, when double bond is changed to single compounds.
(Methane, Ethane, Ethyne, None of these)
30. Hydrogen reacts with halogens to give __________.
(Hydrogen halides, hydrogen hydrides, hydrogen sulphides, All of these)
31. Hydrogen is used in the manufacture of __________.
(Fertilizers, CO2, O2, None of these)
32. Hydrogen at the time of its generation during chemical reaction is in the form of atomic state and is called __________.
(Ionic Hydrogen, Nascent hydrogen, atomic hydrogen, none of these)
33. Hydrogen molecule consists of two atoms linked together by a strong __________.
(Ionic bond, Covalent bond, Hydrogen bonding, None of these)
34. Nascent hydrogen is used in the reduction of __________.
(Ionic compounds, Organic compounds, Inorganic compounds, none of these)
35. The compounds formed between two elements are called __________.
(Hydrides compounds, Binary compounds, Tertiary compounds, None of these)
36. Hydrogen reacts with some elements to form binary compounds called __________.
(Halides, Hydrides, Oxides, all of these)
37. The hydrides formed by the transfer of electrons from electropositive metals to hydrogen are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
38. NaH is an example of __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
39. Ionic hydrides ionize to produce __________.
(H-ion, OH-ion, H+ion, all of these)
40. The hydrides, which are good conductors of electricity in the fused state, are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
41. Covalent hydrides generally exist in __________.
(Solid state, Liquid state, Gaseous state, all of these)
42. Covalent hydrides are prepared by the direct action of __________.
(metals with hydrogen, non-metals with hydrogen, transition elements with hydroge, none of these)
43. Hydrides, which are non-stoichimetric in nature, are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
44. The law of chemical combination is not obeyed by __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
45. Electron deficient hydrides are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
46. Hydrogen occurs in __________.
(One isotopic forms, two isotopic forms, three isotopic forms, four isotopic forms)
47. Atomic hydrogen is __________.
(More reactive than molecular hydrogen, less reactive than molecular hydrogen, very less reactive than molecular hydrogen, all of these)
48. The process of addition of hydrogen to a molecule is called __________.
(Halogenation, Hydrogention, Sulphonation, Reduction)
Chapter 3
S - Block Elements
1. Out of all the elements of group IA, the highest atomic number is for __________.
(Na, Cs, Rb, K)
2. Out of all the elements of group IA, the highest melting and boiling point is for __________.
(Li, Na, Rb, K)
3. __________ of the following elements has highest ionization potential.
(K, Rb, Cs, Li)
4. Out of all the elements of group IA, the highest heat of hydration is for __________.
(Li, Na, K, Rb)
5. __________ of the elements has highest melting and boiling point.
(Be, Ca, Mg, Ba)
6. __________ of the following elements have highest oxidation potential.
(Na, Li, Rb, K)
7. Out of all the elements of group IIA, the highest density at 20°C is for __________.
8. Out of all the following elements of group IIA, the highest atomic number is for __________.
(Be, Ba, ca, Sr)
9. The alkali metals possesses __________ electrons in their outermost orbitals.
(1, 2, 3, 4)
10. Out of all the elements of group IIA, the highest heat of hydration is for __________.
(Be, Ba, Ca, Mg)
11. __________ of the elements has highest ionic radius.
(Be, Ba, Sr, Ca)
12. Out of all the elements of group IA, the highest heat of hydration is for __________.
(Li, Na, K, Cs)
13. Of all the group II elements, the highest oxidation potential is for __________.
(Li, Be, Ba, Ra)
14. Sodium is not observed in +2 Oxidation State because of its __________.
(high first ionization potential, high second oxidation potential, high ionic radius, high electronegativity)
15. The metallic lustre of sodium is explained by the presence of __________.
(Na+ ions, conduction electrons, free protons, a body centred cubic lattice)
16. __________ of the following substances is manufactured by electrolysis of NaCl solution.
(NaOH, Na2ClO3, NaClO3, Na)
17. When NaCl is dissolved in water, the sodium ions become __________.
(Oxidized, Reduced, Hydrolyzed, Hydrated)
18. NaCl imparts a golden yellow colour to the Bunsen flame. This can be interpreted due to __________.
(Low ionization potential of sodium, Photosensitivity of sodium, Sublimation of metallic sodium to give yellow colour, Emission of excess energy absorbed as a radiation in the visible region)
19. The alkaline earth metals possess __________ electron or electrons in their outermost orbitals.
20. Alkali metals form __________.
(Ionic bond, covalent bond, non-polar, Vander waal’s forces)
21. Sodium salts constitute __________% of earth’s crust.
(2.40, 2.35, 2.30, 2.25)
22. Potassium salts constitute __________% of the earth’s crust.
(2.40, 2.35, 2.30, 2.25)
23. Alkaline earth metals occur in nature in __________.
(free state, combined state, both free and combined state, none of these)
24. In general alkali metals act as __________.
(Reducing agents, Oxidizing agents, Both reducing and oxidizing agents, none of these)
25. All alkaline metals except __________ are white in colour.
(Be, Mg, Ca, None of these)
26. In the alkali metal series __________ of the following is most reactive.
(Li, Na, K, Rb)
27. In the alkali metal series, Cesium is the most reactive metal because __________.
(its incomplete shell is nearest to nucleus, the valence electron has a larger orbit than the orbit of the valence electron of any of the others, it exerts considerable Beautiful force on the valence electrons, it is a heavier metal)
28. Alkali metals are __________.
(lighter than water, heavier than water, enlarged than water , all of these)
29. __________ does not belong to alkali metals.
(Li, Na, Rb, K)
30. A graphite anode is used in Down’s cell for the production of sodium because __________.
(It does not react with sodium, it does not react with chorine, it is easy to fashion in circular form, it floats on the fused sodium chloride)
31. __________ is a reducing agent and a constituent of a gun powder.
(KNO3, C, CaCO3, Na)
32. Alkaline earth metals form __________ carbides on heating with carbon.
(Stable, Unstable, soluble, none of these)
33. Except lithium, all alkali metal hydroxides are strongly __________.
(acidic in nature, basic in nature, neutral in nature, none of these)
34. Alkaline earth metal carbonates, sulphates and phosphates are __________.
(soluble in water, insoluble in water, sometimes soluble and sometimes insoluble in water, none of these)
35. Alkali metal carbonates, sulphates and phosphates are __________ in water with the exception of Li2CO3 and Li3PO4.
(soluble, insoluble, Both soluble and insoluble, none of these)
36. LiCl is soluble in organic solvents while NaCl is not. This is because __________.
(Lattice energy of NaCl is less than LiCl, Li+ has higher value of hydration energy than that of Na+, LiCl is more covalent in nature than NaCl, Li+ has lower value of hydration energy than Na+)
37. When burnt in air, Lithium forms __________.
(Normal oxide, Peroxide, Super oxide, none of these)
38. The chlorides of alkali metals and alkaline earth metals are generally __________.
(Ionic, Covalent, non polar, vander waal’s forces)
39. Sodium is a __________.
(good conductor of electricity, poor conductor of electricity, bad conductor of electricity, none of these)
40. Sodium reacts vigorously with oxygen on heating to form __________.
(Sodium oxide, Sodium peroxide, sodium superoxide, all of these)
41. Sodium is very reactive with water. Hence due to its high reactivity with water, it is stored in __________.
(Alcohol, Kerosine oil, Benzene, all of these)
42. Sodium reacts vigorously with water, liberating __________.
(Oxygen, hydrogen, Carbonoxide, Neon)
43. Sodium is a powerful __________.
(Reducing agent, oxidizing agent, bleaching agent, all of these)
44. __________ is used s a reducing agent in the preparation of such metals as titanium and zicronium from their chlorides or oxides.
(Mg, Na, Cu, Ag)
45. __________ is used in the synthesis of rubber.
(Mg, Cu, Na, Fe)
46. __________ reducing action is used in the manufacture of certain dyes and drugs.
(Na, Mg, Cu, Ca)
47. __________ is used often in highway lamps as filaments to produce yellow light.
(Na, Tungston, Mg, Fe)
48. Purification of sodium chloride is accomplished by __________.
(Sublimation, Crystallization, Hydrogenation, Melting)
49. Ice and sodium chloride form a freezing mixture, which is used in __________.
(Refregeration, Preserving fish, Sublimation, None of these)
50. Sodium bicarbonate is commonly called __________.
(Soda Ash, Baking soda, Caustic soda, none of these)
51. Soap is often composed of __________.
(sodium carbonate, calcium carbonate, rubidium carbonate, sodium stearate)
52. Solvay’s process is also called __________.
(Haber’s Proess, Ammonia Soda Process, Washing Soda Process, Down’s Process)
53. __________ is a stronger base.
(NaOH, KOH, LiOH, HCl)
54. Na2CO3 is marketed as __________.
(Soda ash, baking soda, caustic soda, none of these)
55. When a solution of sodium carbonate is evaporated, Na2CO3.10H2O crystallizes out t room temperature and marketed as __________.
(Soda ash, baking soda, caustic soda, washing soda)
56. By the action of aqueous NaOH on aluminium, __________ is produced.
(H2, CO2, H2O, O2)
57. __________ is used for weighing cotton cloth.
(Gypsum, Soda ash, Magnesium Sulphate, Washing soda)
Chapter 4
P - Block Elements
1. __________ of the following is non-metal.
(Boron, Aluminium, Indium, Thallium)
2. __________ of the following was isolated by Davy in 1807 by electrolysis of moist boric acid.
(Boron, Indium, Aluminium, Gallium)
3. __________ of the following is chemically inert.
(Boron, Indium, Aluminium, Gallium)
4. __________ is not the member of group IIIA.
(B, In, C, Al)
5. The oxides of Boron are __________ in nature.
(Acidic, Basic, Neutral, None of these)
6. __________ forms the most acidic oxide.
(B, Al, Ga, In)
7. Boron bursts into flame at __________.
(600°C, 700°C, 800°C, None of these)
8. B3+ cannot exist in aqueous solution because of its __________.
(Strong reducing ability, large size and small charge, small size and large charge, strong oxidizing ability)
9. Orthoboric acid on heating to about 100°C looses a water molecule to form __________.
(Metaboric acid, Pyroboric Acid, Metaboric and Pyroboric acid, none of these)
10. The reduction of metal oxides is sometimes accomplished by using aluminium in the __________.
(Goldshmidt’s reaction, Silberchmdit’s reaction, Baeyer’s reaction, Zilch’s reaction)
11. Baeyer’s Process is used for the purification of __________.
(Alum stone, Cryolite, Bauxite, none of these)
12. Hall’s Process is based on electrolysis of __________.
(Alumina, Gypsum, Borax, none of these)
13. __________ is a better conductor of heat.
(Fe, Sn, Al, none of these)
14. Al2O3 formation involves evolution of a larger quantity of heat, which makes its use in __________.
(Deoxidizer, confectionary, indoor photography, thermite welding)
15. A mixture of iron oxide and aluminium is called __________.
(Thermite, Bauxite, Alum, none of these)
16. Aluminium is used in __________.
(X-ray welding, Spot welding, Thermite welding, none of these)
17. __________ metal is used in photo-flash bulbs.
(Ca, Na, W, Al)
18. The alloy of aluminium, which contains small quantities of manganese, copper and magnesium, is called __________.
(duralumin, Magnalium, Alnico, none of these)
19. The alloy of aluminium with small percentage of magnesium is called __________.
(Duralumin, Magnalium, Alnico, none of these)
20. The aluminium which contains 20% nickel, 20% aluminium, 50% iron and 10% cobalt is called __________.
(Duralumin, Magnalium, Alnico, none of these)
21. A magnet made of __________ will lift approximately 4000 times of its own weight of iron.
(Duralumin, Magnalium, Alnico, none of these)
22. An alloy of aluminium made by alloying 5-15% aluminium and has a golden lustre is called __________.
(duralumin, Magnalium, Aluminium Bronze, none of these)
23. All the alums crystallize to yield __________.
(Octahedral crystal, Tetrahedral crystal, Trigonal crystal, Linear crystal)
24. The process of permanent dyeing is called __________.
(Mordanting, Painting, Calination, none of these)
25. The solvent used in the extraction of aluminium from its ore is __________.
(Cryolite, Bauxite, Molten sodium chloride, Water)
26. The group IV-A of the periodic table consists of __________ elements.
(three, four, five, six)
27. In group IV-A the metallic character down the group __________.
(Increases, Decreases, remains constant, none of these)
28. __________ does not contain aluminium.
(Felsper, Cryolite, Kaoline, Anhydrite)
29. Carbon differs from other members of its group due to the absence of __________ electrons.
(s, p, d, none of these)
30. Elements, which exist in two or more physical or molecular forms, are called __________.
(Isotopes, Allotropes, Isobars, none of these)
31. Out of the following elements of group IV A of the periodic table the higher density is for the element __________.
(C, Si, Ge, Pb)
32. Diamond is a __________ conductor of electricity and heat.
(Poor, Good, None, none of these)
33. Out of all the elements of group IV the higher density is for __________.
(C, Si, Ge, Pb)
34. __________ is used as a lubricant for machinery and also as a moderator in nuclear reactors.
(Diamond, Graphite, Epsom, Gypsum)
35. Highest melting and boiling point is for __________.
(C, Ge, Si, Pb)
36. PbO behaves as a/an __________.
(Amphoteric oxide, basic oxide, super oxide, sub oxide)
37. White lead is prepared by __________.
(Dutch process, Solvay’s Process, Down’s Process, none of these)
38. __________ member of the group V-A show several oxidation states such as –1, +2, +3, +4 and +5.
(P, As, Sb, N)
39. __________ member of the group V-A forms multiple bonds.
(P, Bi, As, N)
40. __________ member of group V-A does not show allotropy.
(P, Sb, N, As)
41. In __________ solution glass is soluble.
(HNO3, HCl, HF, H2CO3)
42. On industrial scale Nitric acid is prepared by __________.
(Dutch Process, Birkland-Eyde’s Process, Solvay’s Process, Down’s Process)
43. In Ostwald’s Process the substance used to oxide ammonia is __________.
(Zn, Pt, CO, none of these)
44. Copper reacts with dilute nitric acid to form __________.
(Nitric oxide, nitrogen peroxide, nitrous oxide, none of these)
45. Nitric acid is a strong __________.
(reducing agent, bleaching agent, oxidizing agent, none of these)
46. A mixture consisting of one volume of concentrated HNO3 and three volumes of concentrated HCl is called __________.
(Aqua regia, Meta stannic acid, Alum, Sandhur)
47. Lead tertraethyle is used as __________.
(Fire extinguisher, Pain Killer, Mosquito repellent, Petroleum Additive)
48. Nitric acid is used in the manufacture of __________.
(Cellulose, Varnishes, T.N.T, all of these)
49. __________ allotropic form of coal is hard.
(Peat, Lignite, Anthracite, Graphite)
50. __________ molecule is paramagnetic nature.
(O, S, Se, Po)
51. __________ element edhibits the largest number of allotropic forms amongst the elements.
52. __________ element is the most abundant element in earth’s crust.
(Ca, Si, C, O)
53. There are __________ rings in unit cell of Rhombic sulphur.
(12, 16, 20, 24)
54. Graphite is used in nuclear reactor as __________.
(A Lurbicant, A fuel, for lining the inside of reactor as an insulator, for reducing the velocity of neutrons)
55. In its unit cell, monoclinic sulphur possesses how many S8 rings.
(12, 6, 3, 0)
56. H2S is a good __________.
(reducing agent, oxidizing agent, bleaching agent, none of these)
57. In the aqueous solution H2S ionizes to produce __________ ions and behaves as a weak acid.
(H+, H-, OH-, none of these)
58. H2S reduces halogens to __________.
(hidrides, halides, halogens, none of these)
59. By __________ process the H2SO4 produced is pure and can be produced of any desired strength.
(Lead Chamber Process, Contact Process, Down’s Cell, none of these)
60. __________ gas is responsible for rising of bread.
(CO, CO2, NH3, O2)
61. At what temperature H2SO4 completely dissociates into sulphur trioxide and water.
(416°C, 516°C, 616°C, 716°C)
62. Concentrated sulphuric acid acts as a __________.
(Reducing agent, Oxidizing agent, Dehydrating agent, None of these)
63. __________ charcoal is used to decolourise brown sugar solution.
(Wood, Coconut, Animal, Sugar)
64. In the sale of diamonds the unit of weight is carat. One cart is equal to __________.
(100mg, 200mg, 300mg, 400mg)
65. Hot concentrated sulphuric acid acts as an __________ usually itself reduced to sulphur dioxide.
(Dehyrating, Oxidizing, Reducing, none of these)
66. __________ are the two elements that find wide application in transistor industry.
(Silicon and Germinium, Carbon and Platinium, Iridium and Germanium, Tungsten and Platinium)
67. In the manufactur of certain explosives such as nitroglycerine, trinitrotoluene and gun-cotton etc. Sulphuric acid is used as a __________.
(Oxidizing agent, Reducing agent, Dehydrating agent, none of these)
68. __________ prepared chlorine in 1774, by the action of hydrochloric acid on manganese dioxide.
(Cavendish, C.W. Scheele, Sir Humphry Davy, Lane)
69. __________ suggested the name chlorine for the gas produced by the action of hydrochloric acid on manganese dioxide.
(Sir Humphry Davy, C.W. Scheele, Cavendish, none of these)
70. Chlorine is obtained by reacting concentrated HCl with __________ agent, such as MnO2, KClO3, KMnO4.
(Reducing, oxidizing, dehydrating, none of these)
71. Electrolysis of Brine produces __________.
(Chlorine, Hydrogen, H2S, Nitrogen)
72. The process based on the oxidation of hydrochloric acid with oxygen is __________.
(Nelson’s Cell, Contact Process, Down’s Process, Deacon’s Process)
73. __________ process is used for the production of chlorine gas.
(Deacon’s, Contact, Solvay’s, Electrolysis of water)
74. Chlorine gas is __________ in colour.
(Yellow, Greenish Yellow, Violet, Blue)
75. __________ produces inflammation of the nose and throat when breathed in considerable quantities.
(Nitrogen, Carbon dioxide, Chlorine, Hydrogen Sulphide)
76. To kill bacterial, molst of the drinking water is treated with __________.
(Nitrogen, Carbon dioxide, Chlorine, Hydrogen Sulphide)
77. Chlorine is used in the preparation of poisonous gases of warfare, such as __________.
(COCl2, H2S, HCl, none of these)
78. In phosphorus oxide the number of oxygen atoms bonded to each phosphorus atom is __________.
(1, 2, 3, 4)
79. Of the following elements the only one which does not exhibit allotropy is __________.
(P, As, Sb, Bi)
80. Phosgene is the common name of __________.
(Carbon dioxide and Phosphine, Phosphoryle chloride, Carbonyle Chloride, Carbon Tetrachloride)
81. Out of all the elements of group VI A, the highest melting and boiling point is for __________.
(Te, Se, S, Pb)
82. In group VIA highest electronegativity is for __________.
(S, O, Pb, Se)
83. Large deposits of sulphur in nature are found as __________.
(Sulphuric acid, hydrochloric acid, free sulphur, none of these)
84. On the basis of available data of the structure of monoclinic sulphur, it probably consists of __________ chains.
(S6, S2, S4, S8)
85. Rhombic sulphur consists of __________.
(S8 chains, S2 chains, S4 rings, S8 rings)
86. Pure sulphuric acid is a solid compound which __________.
(Is always colloidal, slowly decomposes to form SO2, Seves as a useful source for H2S, has never been observed)
87. The form of sulphur, which is stable at room temperature and normal atmospheric pressure, is __________.
(orthorhombic, hexagonal, mono clinic, amorphous)
88. When H2S gas is dissolved in aqua regia, the function of HCl in the mixture is to __________.
(oxidize the sulphur, oxidize the mercury, complex the sulphur, complex the mercury)
89. When liquid sulphur at one atmosphere pressure is very slowly cooled, unless super cooling occurs, the first solid to appear is __________.
(monoclinic sulphur, Rhombic sulphur, Hexagonal sulphur, metallic sulphur)
90. The synthesis of ethers from alcohol depends on the fact that sulphuric acid is a good __________.
(oxidizing agent, reducing agent, complexing agent, dehydrating agent)
91. __________ of the following has the highest catenation capability.
(Oxygen, Sulphur, Selenium, Tellurium)
92. the halogen with the highest ionization potential is __________.
(F, Cl, I, At)
93. The halide ion with the highest hydration energy is __________.
(F-, Cl-, I-, At-)
94. Hydrofluoride acid is __________.
(a powerful oxidizing agent, a weak acid, a strong acid, a good reducing agent)
95. __________ of the following is most powerful oxidizing agent.
(F2, Cl2, Br2, I2)
96. __________ of the following exhibits the largest electrical conductivity in the liquid state.
(F2, Cl2, Br2, I2)
97. __________ of the following exhibits the highest bond energy.
(F2, Cl2, Br2, I2)
98. __________ does not form its oxy acids.
(F2, Cl2, Br2, I2)
99. The colour of I2 solution can be discharged by shaking a aqueous solution of __________.
(Sulphur dioxide, sodium thiosulphate, sodium sulphite, sodium sulphate)
100. Bleaching powder is obtained by the interaction of Cl2 and __________.
(a dilute solution of Ca(OH)2, conc. Solution of Ca(OH)2, dry CaO, dry slaked lime)
Chapter 5
Transition Elements
1. Transition elements are those in which __________ orbitals are in the process of completion.
(d, f, s, d or f)
2. Transition elements are located between __________ elements in the periodic table.
(s and p block, s and f block, d and p block, none of these)
3. Out of total 110 elements known, there are more than __________ transition elements.
(40, 50, 60, 70)
4. Elements in which d-orbitals are in the process of completion are called __________ elements.
(outer transtion, inner transition, non-transition, none of these)
5. __________ of the following is transition element.
(Sr, Sn, Cr, B)
6. __________ of the following elements is not included in the list of transition elements.
(Ca, Cu, Cr, CO)
7. Due to the addition of electrons in inner f-robitals atomic and ionic radii or f-block elements have a regular trend. This is called __________.
(Contraction, Lanthanide contraction, actanide, contraction, none of these)
8. The transition elements usually have very __________ melting and boiling points.
(low, high, intermediate, none of these)
9. Transition elements show a tendency of __________.
(high reactivity, less reactivity, very high reactivity, none of these)
10. Finely divided iron is used in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Contact Process)
11. __________ reagent can be used to identify Cu2+ ion.
(Nitric acid, Sulphuric acid, Sodium hydroxide, Potassium chromate)
12. Vanadium pentaoxide is used in __________.
(Haber Process, Oxidation of sulphur dioxide to sulphur trioxide, oxidation of ammonia to nitric oxide, Contact Process)
13. __________ is the important ore of copper.
(Malachite, Bauxite, Blue Vitriol, Alumina)
14. Copper is used in __________.
(Haber Process, Oxidation of ethyl alcohol to acetaldehyde, oxidation of ammonia to nitric oxide, Contact Process)
15. Bessemer converters are used to get __________.
(Aluminium, Copper, Steel, Sodium)
16. Titanium is used as catalyst in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Polymerization of ethyle into polyethylene)
17. Platinium or Palladium is used as catalyst in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Contact Process)
18. __________ of the following does not belong to d-block elements.
(Chromium, Cobalt, Silicon, Copper)
19. Compounds attracted into a magnetic field are called __________.
(Magnets, Paramagnets, Dimagnets, none of these)
20. Transition metal compounds, which show paramagnetism, have __________.
(unpaired electrons, paird electrons, unpaired protons, paired protons)
21. A substance, which have even number of electrons and have paired spin is called __________.
(Ferromagnetic, Paramagnetic, Dimagnetic, none of these)
22. Magnetic movement is measured with help of __________.
(Guoy’s balance, Spring balance, Physical balance, Cavendish Appratus)
23. __________ property provides information about the presence of unpaired electrons in an atom or ion.
(Dipole moment, Magnetic moment, torque, none of these)
24. By measuring the magnetic moment values we can measure __________.
(Nature of the transition metal compound, oxidation state of the transition metal, both nature and oxidation state of transition metal compound, none of these)
25. Transition elements show variable valencies because of the involvement of the d-electrons in addition to __________.
(p-electrons, f-electrons, d-electrons, e-electrons)
26. The empty spaces between atoms of transition metals in their crystal lattices are called __________.
(Vacant spaces, valence spaces, interstices, none of these)
27. The formation of non-stoichiometric compounds is due to the defects in solid structure and __________.
(Variabel valency of transition elemennts, even number of electrons, even number of protons, unpaired electrons)
28. Interstitial compounds have __________ formula.
(definite, half, indefinite, no)
29. Strong paramegnetism is called __________.
(dimagnetism, ferromagnetism, both dimagnetism and ferromagnetism, none of these)
30. When a number of molecules or negatively charged ions combine with a central d-block atom or ion to form complex ion or molecule, __________ is formed.
(a co-ordinate compound, interstitial compound, di-atomic compound, none of these)
31. In coordinate bonding the molecules or ions, which bond onto the central metal ion or atom, are called __________.
(actanides, Lanthanides, Ligands, none of these)
32. Ligands are __________.
(electron pair donors, electron pair acceptros, neutral, none of these)
33. [Ni(CN)4]2- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
34. [Cu(NH3)4]2+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
35. MnO4- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
36. CrO42- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
37. [Cu(CN)4]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
38. [Zn(NH3)4]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
39. [Fe(CN)6]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
40. [Fe(CN)6]4- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
41. [Ni(NH3)6]2+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
42. [Co(NH3)6]3+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
43. In the system of naming complex coordinate compounds cations are named __________ anions.
(after, beforem, inbetween, none of these)
44. The names of __________ are usually unchanged.
(anionic ligands, cationic ligands, neutral ligands, none of these)
45. NH3 is an example of __________ ligand.
(anionic, cationic, neutral, none of these)
46. H2O is an example of __________ ligand.
(anionic, cationic, neutral, none of these)
47. The suffix “ate” at the end of the name of the coordinate complex ion represents a/an __________.
(cation, anion, cathode, anode)
48. A mixture of iron sulphide and copper sulphide is called __________.
(gangue, matte, matter, residue)
49. Sulphide ore is concentrated by __________.
(Froth floatation Process, Dutch Process, Bessemerization, none of these)
50. __________ does not copper.
(Carborundum, Azurite, Blue Vitriol, Malachite)
51. Utensils used to carry out fermentation are made of __________.
(Cu, Fe, Al, Ca)
52. An alloy of copper, which contains 80% copper and 20% zinc, is called __________.
(Brass, Bronze, Bell metal, none of these)
53. Copper sulphate reacts with solution of potassium iodide giving __________.
(sulphur dioxide, iodine, copper oxide, potassium oxide)
54. An alloy of copper, which contains 90% Cu and 10% Sn is called __________.
(Bronze, Brass, Bell Metal, all of these)
55. An alloy of copper, which contains 80% Cu and 20% Sn is called __________.
(Bronze, Brass, Bell metal, all of these)
56. The substance attracted by magnetic field is known as __________.
(diamagnetic, paramagnetic, antimagnetic, all of these)
57. Copper sulphate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
58. Silver nitrate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
59. Stainless steel is __________.
(a mixture, a compound, an element, all of these)
60. Potassium dichromate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
61. Manganese differs from most other transition elements because it reacts with __________.
(oxygen, water, sulphur, iodine)
62. __________ of the following elements can be included in the category of transition elements.
(Cu, Al, Ar, At)
63. Potassium ferrocyanide is a __________.
(normal salt, mixed salt, double salt, complex salt)
64. __________ of the following combination is included in the Iron triad of elements.
(Pd and Pt, Mn and Hg, Co and Ni, V and Ti)
65. __________ is a blue crystalline solid which is freely soluble in water.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
66. __________ is an orange crystalline solid which is freely soluble in water.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
67. __________ is a yellow crystalline solid which is freely soluble in water.
(Nila Thotha, K2CrO4, Surkh Kahi, none of these)
68. __________ is a colourless crystalline solid.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
69. __________ is used as fungicide and germicide.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
70. Ferric oxide is __________.
(a basic anhydride, an acid anhydride, an amphoteric anhydride, green in colour)
71. Potassium dichromate is a strong __________.
(reducing agent, oxidizing agent, dehydrating agent, all of these)
72. The densest element is __________.
(Pb, Hg, Pt, Os)
73. The most strongly ferromagnetic element is __________.
(Fe, Co, Ni, Os)
74. Alloying of metals serves to inhibit __________.
(Corrosion, Froth Floatation, Erossion, None of these)
75. Mechanical strains can be removed by __________.
(heat treatment, polishing the metal surface, both heat treatment and polishing the metals surface, none of these)
76. __________ has the lowest density.
(Cu, Ni, Sc, Zn)
77. Galvanizing is done by dipping clean iron sheet in a zinc chloride bath and __________.
(heating, rusting, froth floatation, alloying)
78. There are two well known theories to explain the phenomenon of corrosion namely __________.
(Acid theory, Electromechanical theory, electrochemical theory, acid and electromechanical theory)
79. __________ one of the following metals exists in liquid form.
(Sc, Y, La, Hg)
80. The process of depositing a thin layer of tin on base metals to protect them from corrosion is called __________.
(Exposure, tin plating, Fixing, none of these)
81. The most strongly ferromagnetic element is __________.
(Fe, Ni, S, C)
82. The property of a substance which permits it being drawn into wire is called __________.
(softness, Ductility, Brittleness, Hardness)
83. One of the constituent of German silver is __________.
(Ag, Cu, Mg, Al)
84. When potassium permanganate is added to a saturated aqueous solution of potassium hydroxide, __________ gas is evolved.
(Hydrogen, Oxygen, Carbon dioxide, none of these)
85. __________ reagent can be used to identify nickle ion.
(Resorcinol, Dimethyl glyoxime, Dimethyl Benzidine, Potassium Ferrocyanide)
86. __________ of the following is the transition element.
(Sr, Sn, Cr, Fe)
87. Bessemer converters are used to get __________.
(Aluminium, copper, steel, none of these)
88. __________ is not the ore of copper.
(Blue vitriol, Cuprite, Chalcocite, Steel)
89. __________ of the following elements is not included in the list of transition elements.
(Ca, Cu, Cr, Co)
90. __________ one of the following does not belong to d-block elements.
(Chromium, Silicon, Cobalt, Nickel)
Chapter 6
Organic Chemistry
1. The branch of chemistry which deals with the study of compounds containing carbon as a essential element is called __________.
(Organic chemistry, In organic chemistry, Physical chemistry, all of these)
2. The first organic compound synthesized in the laboratory is __________.
(Methane, Urea, Acetic Acid, Glucose)
3. __________ of the following is not an organic compound.
(CH4, CO2, CH2-CH2, CH3OH)
4. __________ of the following is not an organic compound.
(Penicillin, Urea, Oxalic acid, Plaster of Paris)
5. __________ is the important sources of naturally occurring compounds of carbon.
(Animals, Plants, Rock salts, Sea water)
6. __________ is not a component of coal.
(H, O2, N, Si)
7. Hard black form of coal containing 92 – 98% carbon is called __________.
(Anthracite, Sub-bituminous coal, Bituminous coal, Lignite)
8. The most abundant form of coal and is used as energy souce and carbonization for coke, coal tar and coke-oven is called __________.
(Anthracite, sub-bituminous coal, Bituminous coal, Lignite)
9. Form of coal used at power generating stations is called __________.
(Antracite, Sub-bituminous coal, Bituminous coal, Lignite)
10. A soft and brown form of coal which contains 50 to 60% carbon is called __________.
(Anthracite, Sub-bituminous coal, Bituminous coal, Lignite)
11. In Pakistan deposits of lignite are found at __________.
(Dandot, Saindak, Khewra, none of these)
12. __________ is a pure carbon.
(Coke, Coal gas, Coal tar, none of these)
13. Its major constituents are hydrogen (50%), methane (35%) and carbon monoxide (8%).
(Coke, coal gas, coal tar, none of these)
14. Number of organic compounds present in coal tar is __________.
(115, 215, 315, 415)
15. Residue left after fractional distillation of coal tar is called __________.
(Pitch, Dutch, Gangue, Matte)
16. Petroleum in the unrefined form is called __________.
(Coke, Coal gas, Crude oil, Rock oil, both crude oil and rock oil)
17. Natural gas mainly consists of __________.
(Methane, Ethane, propane, Butanes)
18. In Pakistan there are vast reserves of natural gas at __________ in Baluchistan.
(Bandot, Khewra, Saindak, Sui)
19. __________ is a mixture of methane, ethane, propane and butane, used as a fuel and for making other organic chemicals.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
20. __________ is a mixture of hydrocarbons containing 5-8 carbon atoms and boiling in the range of 40-180°C.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
21. __________ is a mixture of hydrocarbons having 11-12 carbon atoms and boiling point in the range of 250°C.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
22. A mixture of hydrocarbons having 13-25 carbon atoms is called __________.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
23. On strong heating the fractions containing the larger hydrocarbon molecules are broken up into smaller and more volatile molecules, this is called __________.
(Sublimation, Cracking, Roasting, Refining)
24. Cracking is also termed as __________.
(Pyrolysis, Refining, Polymerization, Hydrohalogenation)
25. A large number of organic compounds, especially the unsaturated ones, show a great tendency to unite. This process is termed as __________.
(Pyrolysis, Cracking, Polymerization, none of these)
26. An isomer of ethanol is __________.
(Dimethyl ether, Diethyl ether, Ethylene glycol, Methanol)
27. Organic compounds made up of carbon and hydrogen are called __________.
(Polymers, Hydrocarbons, Butanes, none of these)
28. Organic compounds other than the hydrocarbons may be considered to be derived from the hydrocarbons by the replacement of one or more of their __________ atoms with atoms or groups of atoms of other element.
(Carbon, Hydrogen, Nitrogen, none of these)
29. When ethylene is heated under pressure, a transparent solid polymer, __________ is obtained.
(Polyethene, Ethane, Methane, None of these)
30. An atom or group of atoms, which confers characteristic properties to an organic molecule, is called __________.
(Radical, Functional group, Polymer, none of these)
31. Compounds having same molecular formula but different structures are said to be __________.
(Polymers, Isomers, Radical, Functional group)
32. The quality of petroleum is determined by __________.
(Decane number, octane number, hexane number, none of these)
33. __________ of the following obey isomerism.
(CO2, C2H6O, CuSO4, none of these)
34. Two or more than two different compounds having the same molecular formula but different carbon chains or skeletons are said to be __________.
(Chain isomers, position isomers, functional group isomers, metamers)
35. The kind of isomerism which depends upon the relative position of the group, or the position of double or single bond in case of unsaturated compounds in termed as __________.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
36. Isomerism, which involves compounds having the same molecular formula, but different functional groups are called __________.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
37. __________ is exhibited by compounds having the same functional group but different alkyl attached to the same multivalent atom.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
38. In cracking usually catalyst used is __________.
(Pt, Aluminosilicate, Ni, Tetra-ethyl lead)
39. Iso-butane exhibited __________.
(Chain Isomerism, Position Isomerism, Functional group Isomerism, Metamerism)
40. In CCl4 molecule the four valencies of carbon atom are directed towards the corners of a __________.
(Cube, Hexagon, Prism, Tetrahedron)
41. Tetrahedral nature of bonding in carbon atom was first shown by __________.
(Wohler, Vant Hoff and LeBel, Lewis, Kekule)
42. The general formula (RCO)2O represents __________.
(An ether, ketone, an ester, an acid anhydride)
43. Formation of alkane by the action of zinc on alkyl halide is called __________.
(Frankland reaction, Wurtz reaction, Cannizzaro’s reaction, Kolbe’s reaction)
44. __________ of the following are isomers.
(Methyl alcohol and dimethyl ether, Ethyl alcohol and dimethyl ether, Acetone and Acetaldehyde, Proponoic acid and proponanone)
45. The isomers must have the same __________.
(Structural formula, molecular formula, chemical properties, physical properties)
46. __________ has the longest bond length.
(C = C, C º C, C – C, all of these)
47. In alkanes all C – C bonds have __________.
(single bond, double bond, triple bond, none of these)
48. Removal of one of the hydrogen atoms of an alkane produces a __________.
(alkyl group, ethyl group, methyl group, none of these)
49. Compounds in which two alkyl groups are attached to an oxygen atom are called __________.
(alkanes, ethers, alcohals, isomers0
50. Many hydrocarbons contain more than one OH groups in a molecule. Molecules of this type are called __________.
(Ethers, Polyhydroxy alcohols, aldehydes, none of these)
51. __________ is the common name of methanol.
(formaldehyde, acetaldehyde, propionaldehyde, none of these)
52. Compounds which contain carbonyl group but differ from aldehydes in that two alkyl groups are attached to the carbon of carbonyl group are called __________.
(Ethers, Ketons, Alcohols, none of these)
53. __________ is the common name of propanone.
(Acetone , ketone, Diethyl Ketone, none of these)
54. Benzene is a __________.
(Heterocyclic compound, Alicyclic compound, Aromatic compound, Acyclic)
55. Common name of formic acid is __________.
(Methanoic acid, Ethanoic acid, Propanoic acid, none of these)
56. The properties of organic compounds are due to __________.
(Covalent bonds, Functional groups, Ionic bonds, None of these)
Chapter 7
Hydrocarbons
1. Organic compounds, which contain element carbon and hydrogen only are called __________.
(Hyrocarbons, Ethers, Ketones, none of these)
2. The number of hydrocarbons is very large because of the property of hydrogen to __________, with it self in the form of chains and rings.
(Cmbine, Catenate, Sulphonation, none o these)
3. Carbon usually exhibits a covalency of __________.
(Two in most of its compounds, three in most of its compounds, four in most of its compounds, none of these)
4. Hydrocarbons, which contain single bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
5. Hydrocarbons, which contain double bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
6. Hydrocarbons, which contain triple bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
7. The alkanes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
8. The alkynes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
9. The alkenes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
10. Saturated Hydrocarbons are also called __________.
(Alkanes, Olefins, Alkenes, Alkanes and Olefins)
11. Unsaturated hydrocarbons are also called __________.
(Alkenes, Paraffins, alkanes, none of these)
12. Alkenes are characterized by the presence of __________ bond between two carbon atoms.
(single, double, triple, none of these)
13. Alkanes or paraffins are characterized by the presence of __________ bond between two carbon atoms.
(Single, double, triple, none of these)
14. Alkynes are characterized by the presence of __________ bond between two carbon atoms.
(single, double, triple, none of these)
15. Alkanes are also called __________.
(Paraffins, Olefins, Aldehydes, none of these)
16. Alkenes are also called __________.
(Paraffins, Olefins, Carbonyl, none of these)
17. An alkane hydrocarbon chain on cyclization would result in the formation of __________.
(Alicyclic compound, aromatic compound, ethers, none of these)
18. Benzene is the simplest example of hydrocarbon called __________.
(Alicyclic, aromatic, open chain, none of these)
19. Solid CH4 is __________.
(molecular solid, covalent solid, ionic solid, does not exist)
20. Methane is also known as __________.
(oil gas, marsh gas, gasoline, none of these)
21. A liquid hydrocarbon is converted into a mixture of gaseous hydrocarbon by __________.
(Cracking, Hydrolysis, Oxidation, Reduction)
22. __________ is obtained in the laboratory by heating a mixture of sodium acetate and soda lime.
(Alcohol, Ethene, Methane, none of these)
23. Alkenes undergo __________.
(addition reaction, substitution reaction, both addition and substitution reaction)
24. __________ does not react with aqueous solution of acids, alkalies, or potassium permanganate or other oxidizing agents and most of the usual laboratory reagents.
(Benzene, Ether, Methane, Acetic acid)
25. Bromine reacts with methane when the reaction is catalyzed by __________.
(Sunlight, high frequency radiation, diffused sunlight, nickel)
26. In methane the replacement of hydrogen by _ NO2 is called __________.
(Pyrolysis, Nitration, Halogenation, none of these)
27. Methane when heated to extreme temperature in the absence of air undergoes thermal decomposition, called __________.
(Nitration, Catalytic oxidation, Pyrolysis, none of these)
28. Urea, a useful fertilizer, is prepared on industrial scale from __________.
(Natural gas, Coal, Coke, Petroleum)
29. Carbon black is a raw material for paints and automobile tyres and is prepared from __________.
(Ethane, Ethene, Methane, none of these)
30. C2H6 is called __________.
(Methane, Ethane, Methanol, none of these)
31. __________ is obtained in the laboratory by heating sodium proponoate and soda lime.
(Methane, Ethane, Ethene, none of these)
32. In the laboratory ethane is prepared by the reaction called __________.
(Sabatier-Senderens Reaction, Pyrolysis, Catenation, Hydrohalogenation)
33. When an aqueous solution of sodium or potassium salt of mono-carboxylic acid is subjected to electrolytic, corresponding alkane is formed. This reaction is called __________.
(Sabatier-Senderens Reaction, Kolbe’s Electrolysis, Polymerization, chlorination)
34. On burning __________ produces a considerable amount of heat energy which may be used for welding process.
(Ethane, Benzene, Ethene, none of these)
35. __________ is found to be present in wood gas and coal gas.
(Methane, Ethene, Ethane, Benzene)
36. __________ is prepared on a small scale in the laboratory by heating together ethyl alcohol and sulphuric acid.
(Methane, Ethane, Ethylene, none of these)
37. The elimination of hydrogen halide (HX) from adjacent carbon atoms is called __________.
(Pyrolysis, Chlorination, Dehydrohalogenation, none of these)
38. __________ process is important in the hardening of vegetable and animals oils to produce solid fats which are used to make margarine.
(Pyrolysis, Catenation, Hydrogenation, Dehydrohalogenation)
39. When a mixture of ethene and air is passed over heated silver under pressure, we get __________.
(Epoxide, Superoxide, Suboxide, none of these)
40. The negative part of the addendum adds on to the carbon atom joined to the least number of hydrogen atoms. The statement is called __________.
(Markownikoff’s rule, Peroxide effect, Theile’s theory, Baeyer’s strain theory)
41. Baeyer’s test is the basis for detection of a __________ bond in an organic molecule.
(single, double, triple, none of these)
42. __________ was used in first world war.
(Phosgene gas, Mustard gas, Oil gas, Coal gas)
43. When a mixture of CO, C2H4 and C2H2 is passed through ammonical cuprous chloride solution then __________.
(Acetylene and CO are absorbed, CO is absorbed, C2H4 is absorbed, Nothing happens)
44. Ethylene dichloride is also called __________.
(Mustard gas, Dutch liquid, Polyethene, none of these)
45. __________ is used to manufacture mustard gas which is poisonous gas used as war gas.
(Ethane, Methane, Ethylene, none of these)
46. __________ is most found in alkenes.
(Chain isomerism, Geometrical isomerism, Mesomerism, Position Isomerism)
47. __________ poisonous gas is present in the exhaust fumes of car.
(Methane, Acetylene, HCl, Carbon dioxide)
48. __________ is used to import colour to stile green citrus fruit form ripening.
(Ethylene, Methane, Ethane, none of these)
49. The number of xylene isomers is __________.
(2, 3, 4, 5)
50. Ethylene dichloride and ethylene chloride are isomeric compounds. The statement which is not applicable to both of them is __________.
(react with alcoholic potash, react with aqueous potash and give the same product, are dihalides, answer Beilstein’s test)
51. Structure of benzene is __________.
(Diagonal, Planner, Pyramidal, Tetrahedral)
52. __________ is used in the manufacture of plastic and synthetic rubber.
(Styrene, Mustard gas, Polythene, none of these)
53. The polythene is a polymer of __________.
(Ethylene, Aceton, Propylene, Butadiene)
54. Acetylene or ethyne was discovered accidentally in 1899 by the American chemist __________.
(Wilsson, Lane, Nelson, none of these)
55. Acetylene is present in small proportions (about 0.06% by volume) in __________.
(Natural gas, Coal gas, Gasoline, Petroleum)
56. __________ is prepared in the laboratory by dropping water on calcium carbide.
(Ethylene, Acetylene, Methane, none of these)
57. The process used for the preparation of acetylene is __________.
(Berthelot Process, Sabatier-Senderns Reaction, Kolbe’s Process, none of these)
58. Acetylene has a characteristic ethereal smell resembling that of __________.
(Rotten egg, Garlic, Benzene, none of these)
59. Acetylene burns with __________ flame.
(Greenish, Bluish, Smoky, none of these)
60. Benzene was found by __________ in 1825 in the gas produced by the destructive distillation of vegetable oils.
(Hofmann, Michael Faraday, Solvay, none of these)
61. __________ found benzene in coal-tar.
(Hofmann, Michael Faraday, Solvay, none of these)
62. When n-hexane obtained from petroleum is heated in the presence of platinum at 500°C under 10 – 20 atmosphere pressure, it cyclises to give __________.
(Ether, Benzene, Mustard Gas, none of these)
63. Phenol is reduced to __________, when its vapours are passed over red hot zinc dust.
(Ether, Benzene, Ethane, Acetylene)
64. Replacement of hydrogen atom by – SO2 OH is called __________.
(Nitration, Sulphonation, Alkylation, Hydrogenation)
65. _ SO2OH is called __________.
(Sulphonic Group, Carbonyl group, Methyl group, none of these)
66. Under the influence of anhydrous aluminium chloride as a catalyst, benzene reacts with alkyl and acyl halides giving alkylated and acylated benzens. The reaction is called __________.
(Friedel-Cracts Reactions, Berthelot’s Reaction, Sabatier-Senderens Reaction, none of these)
Chapter 8
Alkyl Halides
1. Monohalo derivatives of alkanes are called __________.
(Acyl halides, Aryl Halides, Alkyl Halides, none of these)
2. The general formula of alkyl halides is __________.
(CnH2n+1 X, CnHn+1 X, C2nH2n+1 X, none of these)
3. When an alkene is treated with halogen acids, __________ is formed.
(Alkyl halide, Acyl halide, Carbonyl chloride, all of these)
4. Formula of Thionyl Chloride is __________.
(SOCl2, ZnCl2, CH3Cl, none of these)
5. If ethane is treated with HBr then __________.
(Ethyl bromide is formed, Methyl bromide is formed, Bromine is evolved, Hydrogen is obtained)
6. When metallic sodium in ether is heated with an alkyl halide, a higher alkane is formed. It is called __________.
(Sulphonation, Wurtz’s Reaction, Friedel-Crafts Reaction, none of these)
7. If sodium lead alloy is treated with methyl chloride then __________.
(Tetra ethyl lead is formed, Tetra methyl lead is formed, Tri methyl lead is formed, Di methyl lead is formed)
8. Dehydrohalogenation of alkyl halide is carried in the presence of alcoholic __________.
(NaOH, KOH, Ca(OH)2, none of these)
9. Grignard’s reagent when reacts with ammonia then __________.
(Methane is formed, Ethane is formed, Nitrogen is evolved, Magnesium is separated)
10. Grignard’s reagent reacts with alkyl halide to form __________.
(Alkanes, Alkynes, Alkenes, Alcohols)
11. Grignard’s reagents are __________.
(Alkyl halide, Alkyl magnesium halide, Alkyl sodium halide, none of these)
12. On passing CO2 through Grignard reagent __________ is formed.
(Methanoic acid, Ethanoic acid, Propanoic acid, No reaction occurs)
13. Alkyl halides (methyl chloride or ethyl chloride) when treated with __________, react to produce the important anti-knock gasoline additives.
(Sodium, Lead, Sodium-lead Alloy, none of these)
14. On adding formaldehyde to Grignard’s reagent __________ is formed.
(Primary alcohol, Secondary alcohol, Aldehyde, Acetone)
15. Action of zinc with alkyl halide in the presence of an inert solvent forms a corresponding higher alkane. This is called __________.
(Wurtz’s Reaction, Frankland Reaction, Hoffman’s Reaction, none of these)
16. The hydrolysis of alkyl halides by heating with aqueous alkali is a __________ substitution reaction.
(Electrophilic, Nucleophilic, Electrophile and Nucleophile, none of these)
17. __________ of the following compounds does not react with bromine.
(Ethylamine, Propene, Phenol, Chloroform)
18. A reaction in which an atom or group of atoms replaces an atom or group of atoms already present in the molecule of a substance is called __________.
(Nitration, Halogenation, Substitution, Sulphonation)
19. __________ is a Neucliphile.
(OH-, CN-, NH3, all of these)
20. General formula of Grignard’s reagent is __________.
(R – Mg – X, R – Al – X, R – Na – X, R – Cl – X)
21. __________ is prepared by heating methyl iodide with fresh magnesium turnings in anhydrous ether.
(Grignard’s reagent, Mustard gas, Benzene, none of these)
22. When Grignard’s reagent is hydrolyzed with water, it is converted into __________.
(Alkynes, Alkenes, Alkanes, Acetons)
23. __________ of the following alkyl halides is used as a methylating agent.
(C2H5Cl, C2H5Br, C2H5I, CH3I)
24. Ethyl chloride reacts with alcoholic KOH to give __________.
(C2H5OH, C2H6, C2H2, C2H4)
25. Dry carbon dioxide is passed through Grignard’s Reagent in the presence of __________ as a solvent.
(Acetone, Benzene, Ether, none of these)
26. Grignard’s reagent reacts with CO2 to form __________.
(HCl, Carboxylic acid, Acetic acid, Carbonic acid)
27. Grignard’s reagent reacts with acetaldehyde to form __________.
(Primary alcohol, Secondary alcohol, Tertiary alcohol, all of these)
28. Alkyl halides reacts with Zn to form __________.
(Alkynes, Alkanes, Alkenes, none of these)
Chapter 9
Organic Compounds
1. The action of nitrous acid on ethyl amine gives __________.
(Ethane, Ammonia, Ethyl alcohol, Nitroethane)
2. Isopropyl alcohol on oxidation gives __________.
(Ether, Acetone, Ethylene, Acetaldehyde)
3. Rectified spirit contains __________ % alcohol.
(95.6, 75.0, 100.0, 85.4)
4. __________ is the end product in the process of fermentation.
(Methyl alcohol, Ethanol, CH3OH, Ethylene)
5. __________ is not the characteristic of the alcohols.
(Their boiling points rise fairly uniformly with a rise in molecular weight, Lower members have a pleasant smell but burning taste and the higher ones are odourless and tasteless, these are lighter than water, Lower members are soluble in water and organic solvents but solubility decreases with increase in molecular weight)
6. In the dehydration of ethyl alcohol to ethylene with concentrated sulphuric acid __________.
(Carbonium ions are involved, carbonium are evolved, sulphuric acid acts as an electrophile, none of these)
7. A compound is an/a __________ if the “R-” group is derived from aliphatic or alicyclic hydrocarbons.
(Ether, Ketone, Alcohol, Phenol)
8. A compound which has –OH group attached to an aromatic hydrocarbon is called __________.
(Alcohol, Phenol, Ether, none of these)
9. A product formed by the reaction of sodium with ethanol is __________.
(H2O, NaOH, NaH, H2)
10. An alcohol, which contains on –OH group is called __________.
(Monohydric, Dihydric, Trihydric, none of these)
11. An alcohol, which contains on –OH group is called __________.
(Monohydric, Dihydric, Trihydric, none of these)
12. Primary, secondary and tertiary alcohols may be distinguished by using __________.
(Fehling’s solution, Victor Meyer test, Hofmann set, Beilstein test)
13. The number of structural isomers for C4H9OH is __________.
(3, 4, 5, 6)
14. In cold countries glycerol is added to water in car radiators as it helps to __________.
(bring down the specific heat of water, lower the freezing point, reduce the viscosity, make water a better lubricant)
15. Aldehydes and Ketons are commonly referred to as __________.
(Ethers, Carbonyl compounds, phenols, none of these)
16. Aldehyde may be distinguished from ketons by the use of __________.
(Concentrated Sulphyric acid, Grignard’s Reagent, Pyrogallol, Fehlings solution)
17. In aldehydes one bond of carbonyl group is always attached to __________.
(Carbon atom, Hydrogen atom, Nitrogen atom, none of these)
18. An aldehyde on oxidation gives __________.
(an alcohol, a ketone, an acid, an amine)
19. Acid anhydrides are calls of carboxylic acid derivatives, which may be formed by the elimation of __________.
(Carbon, Hydrogen, Water, none of these)
20. Formaline is an aqueous solution of __________.
(Formic acid, Formaldehyde, Flurescein, Furfuraldehyde)
21. Methyl alcohol is known commercially as __________.
(Wood-spirit, Wood Naphtha, Mustard gas, both Wood spirit and Wood- Naphtha)
22. __________ discovered Methyl alcohol.
(Boyle, Salvay, Jabber Bin Hayyan, none of these)
23. When wood is heated with an insufficient supply of air, organic materials are driven off as gases, and the cellulose is decomposed to almost pure carbon is called __________.
(Coal, Charcoal, Oil gas, Natural gas)
24. Now a days a large quantity of methyl alcohol is obtained by passing __________ over heated zinc and chromium oxides at 400 - 450°C under 200 atmospheric pressure.
(Natural gas, Water gas, Ethylene, none of these)
25. Methyl alcohol can cause __________.
(Cancer, Blindness, Aneimia, none of these)
26. The reaction of alcohol with thionyl chloride (SOCl2) in the presence of solvent called __________.
(Pyridine yields, Adenine yields, Guanine yields, none of these)
27. Ethyl alcohol often called __________.
(Alcohol, Spirit, Ether, Lacquer)
28. Ethyl alcohol is also called __________.
(Methyalted spirit, Spirit of wine, Wood spirit, none of these)
29. __________ is also present in the urine of diabetic patients.
(Spirit of wine, Wood spirit, Methane, none of these)
30. In 1808, __________ discovered ethyl alcohol in urine of diabetic patients.
(Boyl, Suassure, Mendleeve, none of these)
31. Ethyl alcohol is produced on commercial scale by the biological break down of __________,
(Starch, Minerals, Cellulase, None of these)
32. The 14 enzymes present in the living cells of the yeast are collectively called __________.
(Substrate, Zymase, Amylase, none of these)
33. The force of attraction of the electrons of one atom for the protons of another atom in close proximity is called __________.
(Ionic bond, Hydrogen bond, Covalent bond, all of these)
34. __________ of the following compounds can form a hydrogen bond.
(CH4, H2O, NaCl, CHCl3)
35. When two ice cubes are pressed over each other, they unite to form one cube. __________ of the following forces is responsible to hold them together.
(Hydrogen bond formation, Vander Waal’s forces, Covalent bond, Dopole Interaction)
36. CH3OH and C2H5OH are highly miscible with water because they exhbits __________.
(Ionic bonding, Covalent bonding, Hydrogen bonding, none of these)
37. Alcohols may be converted to the corresponding __________ by actions of halogen acids in the presence of ZnCl2.
(Aldehydes, Alkyl halides, acyl halides, none of these)
38. Compounds obtained by the elimination of a molecule of water between an alcohol and hydroxyl group of the acid are called __________.
(Ethers, Esters, Ketons, Phenols)
39. During the dehydration of alcohols, relatively high temperature and moderate alcohol concentration yield the corresponding __________.
(Ether, Olefin, Paraffin, none of these)
40. Ethyl alcohol may be identified by the __________.
(Bayer’s Test, Flame Test, Idoform Test, Chloroform Test)
41. Industrially, formaldehyde is made from methyl alcohol by __________.
(Dehydrogenation, Dehydrohalogenation, Oxidation, Reduction)
42. Dry distillation of calcium formate yields __________.
(Ether, formaldehyde, Acetic acid, none of these)
43. An aldehyde is converted to carboxylic acid on __________ with K2Cr2O7 and H2SO4.
(Reduction, Oxidation, Dehydrogenation, all of these)
44. When aldehydes are warmed with __________, red precipitates of cuprous oxide are precipitated.
(Grignard’s Reagent, Fehlings solution, KMnO4, none of these)
45. Aldehydes can be distinguished from Ketons by using __________.
(Schiff’s reagent, Concentrated sulphruric acid, Anhydrous Zinc chloride, Resorcinol)
46. In ketons the two bonds of the carbonyl are attached to two __________.
(alkyl group, aryl group, hydrogen group, alkyl group and aryl group)
47. Formation of acetaldehyde from ethanol is called __________.
(Addition, Reduction, Oxidation, Substitution)
48. Aldehydes can be distinguished from ketons by __________.
(AgNO3, CH3COOH, conc. H2SO4, Fehlings solution)
49. Acetaldehyde reacts with __________.
(nucleophiles only, electrophiles only, free radicals only, both with nucleophiles and electrophiles)
50. When aldehydes are warmed with a ammonical solution of silver nitrate, they precipitated metallic silver which often form a mirror. This reaction is called __________.
(Tollen’s Test, Fehlings Test, Idoform Test, none of these)
51. Acetaldehyde reacts with ammonia to form __________.
(Condensation products, substitution products, addition product, resin like product)
52. __________ prepared the first synthetic plastic, by combing formaldehyde with phenol under heat and pressure.
(Newlands, Blackeland, Russel, Charles)
53. __________ is used medically as a urinary antiseptic.
(Formaldehyde, Benzene, Sulphuric acid, Methanamine)
54. Aldol condensation can occur between __________.
(an aldehyde and ketone, an aldehyde and ester, an aldehyde and benzene, none of these)
55. Aldol condensation between __________ of the following compounds, followed by dehydration gives methyl vinyl ketone.
(HCHO and CH3COCH3, HCHO and CH3CHO, Two molecules of CH3CHO, Two molecules of CH3COCH3)
56. Aldol condensation can occur between __________.
(two aldehydes (identical or different), an aldehyde and ester, an aldehyde and benzene, none of these)
57. Aldol condensation can occur between __________.
(two aldehydes and phenols, two ketons(identical or different), an aldehyde and benzene, none of these)
58. A nucleophilic addition of carbonion, generated by the loss of proton from a-position of an aldehyde or a ketone by a base, to the carbonyl group, is called __________.
(Nitration, Aldol Condensation, Esterification, none of these)
59. The aldehydes having no hydrogen attached to a-carbon atom when treated with concentrated solution of an alkali, undergo self-oxidation and reduction, forming a mixture of an alcohol and a salt of corresponding carboxylic acid. The reaction is known as __________.
(Fehlings reaction, Cannizzaro reaction, Formalin reaction, none of these)
60. An aqueous solution containing about 40% of formaldehyde and a little alcohol is sold under the name of __________.
(Formalin, Malt-sugar, Pyridine, Starch)
61. Gelatine, a substance readily soluble in water, becomes insoluble when it is treated with __________.
(Formalin, Malt sugar, Benzene, Resins)
62. __________ is used as preservative for biological specimens.
(Benzene, Ketone, Alcohol, Formaline)
63. Alive polio virus in the culture fluid is made harmless by addition of __________ in the processing of anti-virus vaccine.
(Benzene, Acetic acid, formaldehyde, Carboxylic acid)
64. Acetic acid is manufactured from the brown aqueous distillate known as __________ which is obtained by the destructive distillation of wood and contains a mixture of acetic acid, acetone and methyl alcohol.
(Formalin, Pyroligenous acid, Pyridine, Acetylene)
65. The most general method of preparing __________ is by oxidation of corresponding aldehydes or primary alcohols.
(Phenols, Carboxylic acids, ketones, none of these)
66. The chemical properties of the carboxylic acids depend chiefly on the __________.
(Hydroxyl group, Carbonyl group, Methyl group, none of these)
67. __________ is used for coagulating rubber and latex and curing fish as well.
(Alcohol, Acetic acid, Wood spirit, none of these)
68. Ethyl acetate is an example of a important class of substance known as __________.
(Ketones, Esters, Alcohols, none of these)
69. Ethyl acetate (an ester) can be prepared by the action of __________ on carboxylic acid, in the presence of acidic media.
(Phenols, Formalin, Pyradine, Alcohol)
70. Molecular hydrogen in presence of suitable catalysts reduces carbonyl compounds to __________.
(aCetones, Ethers, Esters, Alcohols)
71. __________ is used as a nail-polish remover.
(acetone, Benzene, Idoform, none of these)
72. Acetone may be converted into propane by heating with __________.
(conc HCl and 24/Hg, Mg + H2O, conc HI and red P, Zn/Cu couple and ethanol)
73. __________ is the solvent used in the preparation of Grignard’s reagent and in Wurtz reaction.
(Ethers, Phenoles, Ketons, Alcohols)
74. The hydroxyl group derivatives of aromatic hydrocarbons, which have the –OH group directly bonded to the ring carbon atoms are called __________.
(Esters, Acetons, Alcohols, Phenols)
75. Carbolic acid is prepard from __________.
(Dow’s Process, Down’s Process, Nelson’s Process, none of these)
76. Phenol is colourless, poisonous __________.
(Liquid, Gas, Solid, none of these)
77. Above __________ °C phenol is miscible with water in all proportions, but below this temperature, it is only partially miscible.
(78.5, 68.5, 58.5, none of these)
78. Phenol is reduced to __________ when its vapours are passed over red hot zinc dust or distilled in the presence of zinc dust.
(Alcohol, Benzene, acetone, none of these)
79. Action of zinc with alkyl halide in the presence of an inert solvent forms a corresponding higher alkane. This is called __________.
(Wurtz’s reaction, Frankland’s reaction, Hoffman’s reaction, none of these)
80. The hydrolysis of alkyl halides by heating with aqueous alkali is a __________ substitution reaction.
(Electricphilic, Nucleophilic, Electrophilic and Nucleophilic, none of these)
81. __________ is prepared by heating methyl iodide with fresh magnesium turnings in anhydrous ether.
(Grignard’s reagent, Mustards gas, Benzene, none of these)
82. Dry carbon dioxide is passed through Grignard’s reagent in the presence of __________.
(Acetone as a solvent, Benzene as a solvent, Ether as a solvent, none of these)
Chapter 10
Chemistry of Life
1. Starch is a polymer of __________.
(Glucose, Fructose, Lactose, Maltose)
2. A material cannot be termed as food unless it contains at least one __________.
(Vitamine, Mineral, Nutrient, Amino acid)
3. On heating glucose with Fehling’s solution we get a precipitate of colour __________.
(Yellow, Red, Black, Green)
4. It is the best to carry out reactions with sugars in neutral or acid medium and not in alkaline medium. This is because in alkaline medium sugars undergo __________ of the following changes.
(Racemisation, Decomposition, Inversion, Rearrangement)
5. __________ food component regulates body processes.
(Minerals, Fats, Proteins, Carbohydrates)
6. The process by which large non-diffusuble organic molecules are converted into smaller diffusible molecules is known as __________.
(Ingestion, Fermentation, Decomposition, Digestion)
7. The solution of sugar in water contains __________.
(Free atoms, Free ions, Free molecules, Free atoms, and free molecules)
8. During digestion carbohydrates are broken down to __________.
(Glucose, Amino acids, Fatty acids, None of these)
9. During digestion proteins are broken down to __________.
(Glucose, Amino acids, Fatty acids, none of these)
10. __________ of the following gives a deep blue colour with a drop of dilute solution of iodine.
(Cellulose, Glucose, Starch, Sugar)
11. During digestion fats are broken down to __________.
(Glucose, Amino acids, Fatty acids, none of these)
12. The use of the products of digestion in synthesis of cellular structure is known as __________.
(Metabolism, Assimilation, Homeostasis, None of the above)
13. The percentage of glucose in human blood is __________.
(0.1, 0.2, 9.3, 0.4)
14. Carbohydrates supply about __________ of energy per gram.
(4 kcal, 2 kcal, 2 kcal, 1 kcal)
15. The main source of cellulose is __________.
(cotton, wood, both cotton and wood, none of these)
16. Fats provide about __________ of energy per gram.
(4kcal, 2 kcal, 9kcal, 5kcal)
17. Of the following, __________ is a high-energy food.
(Proteins, Fats, Carbohydrates, none of these)
18. Glucose and fructose are __________.
(Geometrical Isomers, Metamers, Optical Isomers, none of these)
19. __________ isomers of glucose are known.
(4, 8, 16, 32)
20. The digestion of carbohydrates begins with the mastication in the mouth, where enzyme __________ of the saliva hydrolyses some of the starch to maltose.
(Ptyalin, Amylase)
21. Human body tissue contains __________% carbohydrates.
(1, 2, 3, 4)
22. Carbohydrates are ultimately converted into glucose and other simpler products in the __________.
(Mouth, Stomach, Small intestine, Large intestine)
23. The use of products of digestion in synthesis of cellular structures is called __________.
(Assimilation, Metabolism, Excretion, Digestion)
24. The products of oxidation of glucose are __________.
(Carbon dioxide and water, Oxygen and Hydrogen, Carbon dioxide and hydrogen, none of these)
25. Glucose is termed as __________.
(Single nutrient food, double nutrient food, multi nutrient food, none of these)
26. Deficiency of all nutrients leads to __________.
(Nutrition, Malnutrition, Under Nutrition, none of these)
27. The recommended daily intake of protein per kilogram of the body weight is __________.
(0.8 gm, 0.9 gm, 0.6 gm, 1.0 gm)
28. Lipids and Proteins are made of __________.
(Macromolecule, Micromolecule, Microatom, None of these)
29. The digestion of proteins begins in the __________.
(Mouth, Stomach, Small intestine, Large intestine)
30. The enzyme __________ of gastric juice, catalyses the hydrolysis of peptide linkage in protein molecules.
(Renin, Trypsin, Pepsin, Amylase)
31. In the mouth of some of the starch is hydrolyzed to maltose by the action of enzyme __________.
(Ptylin, Lipase, Renin, Amylase)
32. In the body dietary proteins are the source of __________,
(Amino acids, Fatty acids, Lipids, none of these)
33. A large class of compounds that are polyhydroxy aldehydes or ketones, or substances that yield such compounds upon acid hydrolysis are called __________.
(Fats, Carbohydrates, Proteins, vitamins)
34. Plants are able to synthesis their own carbohydrates from CO2 of the air and water taken from the soil in the presence of sunlight and chlorophyll. This process is called __________.
(Nutrition, Assimilation, Photosynthesis, Homeostasis)
35. Human diet consist of 60 – 65% by mass of the average diet on __________.
(Fats, Carbohydrates, Proteins, vitamins)
36. Carbohydrates, which have three to nine carbon atoms and are not hydrolysable are called __________.
(Monosacchrides, Ddi-saccharides, Poly-saccharides, None of these)
37. The carbohydrates, which have three to nine carbon atoms and are not hydrolysable are called __________.
((Monosacchrides, Ddi-saccharides, Poly-saccharides, None of these)
38. The balanced diet contains amount __________ per day.
(60 gm, 70 gm, 80 gm, 90 gm)
39. Glucose is __________.
(a monosacchride carbohydrate, a di-saccharide carbohydrate, a poly-saccharide carbohydrate, none of these)
40. A class of carbohydrates which are formed by the condensation of two or more monosaccharide units with the loss of water molecules are called __________.
(Disaccharides, Poly saccharides, Pentoses, none of these)
41. Sucrose is an example of __________.
(a monosacchride carbohydrate, a di-saccharide carbohydrate, a poly-saccharide carbohydrate, none of these)
42. On hydrolysis __________ is broken down into two simpler sugars glucose and fructose.
(Glucose, Sucrose, Maltose, none of these)
43. Glucose is also called __________.
(Dextrose, Maltose, Fructose, Mannose)
44. Corn syrup contains __________.
(Glucose, Fructose, Mannose, Maltose)
45. Fructose occurs in many __________.
(Cereals, Fruits, Vegetables, none of these)
46. Honey is a mixture of __________.
(Glucose and Fructose, Glucose and Maltose, Fructose and Mannose, Glucose and Fructose with vitamins and minerals)
47. The carbohydrates, which contain hundreds to thousands of monosacchride units are called __________.
(Polysacchrides, Oligosaccharides, Hexoses, None of these)
48. Cellulose is an example of __________.
(Monosaccharides, Di-saccharides, Polysaccharides, None of these)
49. The main difference between starch and cellulose is the type of links between __________.
(Mannose units, Glucose units, Fructose, units, none of these)
50. Vitamin was discovered by __________.
(Casimir Funk, Blackeland, Hopkins, Elmer)
51. Vitamin A was discovered by __________.
(Elmer McCollum, Casimir funk, Hopkins, none of these)
52. Vitamin D was discovered by __________.
((Elmer McCollum, Casimir funk, Hopkins, none of these)
53. Fat-soluble vitamins are found associated with __________ in natural foods.
(Renin, Lipids, Peptides, Maltose)
54. Fat soluble vitamins include __________.
(Vitamin A, B, C, D, Vitamin A, B, C, Vitamin A, D, E, K, Vitamin K)
55. Water-soluble vitamins include __________.
(Vitamin A, B, Vitamin A, B, C, vitamin B, C, Vitamin A, C)
56. Vitamin B1 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
57. Vitamin B2 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
58. Vitamin B5 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
59. Vitamin B6 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
60. Vitamin B12 is called __________.
(Cyanocoalamine, Riboflavin, Niacin, Pyridoxine)
61. Most water-soluble vitamins act as __________.
(Enzymes, Coenzymes, Coenzymes or are required for the synthesis of coenzymes, none of these))
62. People who consume too much vitamin __________, may develop bone pain, bone like deposits in the kidneys, and mental retardation.
(A, B, C, D)
63. Edible lipids constitute approximately __________ % of the diet of an average person.
(25-28, 25-30, 25-32, 25-35)
64. The most important energy storage compounds in the animal kingdom are __________.
(Peptides, Lipids, Amino acids, none of these)
65. Plants store most of the energy in the form of carbohydrates primarily as __________.
(Amino acids, Starch, Cellulose, Maltose)
66. The nutrients of our food which provide insulation for the vital organs, protecting them from electrical shocks and maintaining optimum body temperature are called __________.
(Amino acids, Steroids, Lipids, Fatty acids)
67. Lipids that contain both polar and non polar groups are integral components of __________.
(Cell wall, Cell membrane, Cytoplasm, Mitochondria)
68. Steroids is an important type of __________.
(Proteins, Vitamins, Lipids, Carbohydrates)
69. The most abundant and the most important steroid in the human body is __________.
(Riboflavin, Cholestrol, Folic acid, Inositol)
70. __________ is an important precursor in the biosynthesis of sex-hormones, synthesis of adrenal hormones and vitamin D.
(Insitol, Cholestrol, Lipoic Acid, Biotin)
71. On the average, more than 50% of the total dry weight of the cells is composed of __________.
(Carbohydrates, Proteins, Fats, Water)
72. The Dutch chemist, GJ Mulder (1883), is credited as being one of the first scientists to recognize the importance of __________.
(Vitamins, Carbohyrates, Proteins, Fats)
73. __________ organic compound is a major structural component of an animal tissue.
(Carbohydrates, Proteins, Cellulose, Lipids)
74. Hormones are made of __________.
(Proteins, Fats, Carbohydrates, Lipids)
75. Antibodies are __________.
(fats in nature, carbohydrates in nature, protein in nature, vitamins in nature)
76. Enzymes are __________.
(carbohydrates in nature, proteins in nature, fats in nature, none of these)
77. Haemoglobin is a __________.
(Protein, Carbohydrate, Fat, Mineral)
78. The primary function of proteins is __________.
(Energy supply, body building, body building and maintenance, protection of body)
79. __________ nutrients of food are stored by the body as energy reserves.
(Carbohydrates and lipids, proteins and lipids, proteins and carbohydrates, none of these)
80. for a normal adult with a constant weight, the recommended daily intake of protein is approximately __________ gram per kg of body weight.
(0.2, 0.4, 0.6, 0.8)
81. 33% - 43% protein is present in __________.
(Food yeast, Soya bean, Rice, Cheese)
82. The percentage of protein in chicken food is __________%.
(28, 21, 33, 12)
83. The protein in milk is __________%.
(2, 3, 12, 19)
84. Fats are esters of glycerol and __________.
(Faty acids, Lipids, Steroids, none of these)
85. The percentage of protein in egg is __________%.
(12-18 , 12-24, 12-36, 12-48)
86. The percentage of protein in flour is __________%.
(18, 12, 6, 3)
87. The percentage of protein in fish is __________%.
(18-21, 12-18, 6-36, 3-9)
88. The percentage of protein in rice is __________%.
(6-7, 2-3, 5-11, 11-19)
89. The percentage of protein in fresh vegetables is __________%.
(5-6, 7-17, 4-7, Rarely contains 2-3)
90. Amino acids are the building blocks of __________.
(Carbohydrates, Proteins, Lipids, Fats)
91. Proline amino acids have __________ group and –COOH group attached to the same carbon atom.
(-NH3, -NH2, -NH, -OH)
92. Amino acids are widely classified __________.
(according to the number of –NH2 group, according to the number of –COOH group, according to polarity of their side chain, all of these)
93. The first amino acid was isolated in 1806 and was given the name __________.
(Asparangine, Glycine, Renin, Maltose)
94. The major amino acid found in gelatin is __________.
(Glycine, Asparangine, Renin, none of these)
95. Esters of Glycerol and Fatty acids are called __________.
(Acids, F, Proteins, Carbohydrates)
96. Among the most important of the natural __________ are the cotton seed oil, corn oil, butter, tallow and olive oil.
(Fats, Proteins, Carbohydrates, Vitamins)
97. Unsaturated vegetable oils, such as cotton seed oil are converted into fast on __________.
(Oxidation, Dehydration, Hydrogenation, Sulphonation)
98. The hydrogenation of oils is accomplished easily by bubbling hydrogen into the oil in the presence of catalyst __________.
(Pt, Ni, Zn, ZnO)
99. Naturally occurring fatty acid nearly always have an/a __________ number of carbon atoms.
(Even, Odd, Even and odd, none of these)
100. Liquid fats are called __________.
(Fatty acids, Oils, Ketones, Lipids)
101. The degree of undaturation of a fat or oil is usually measured by the __________.
(number of carbon atoms, number of hydrogen atoms, iodine number, none of these)
102. The number of grams of iodine that will be consumed by 100 grams of fat or oil is called __________.
(Iodine complex, Iodine number, Iodoform, None of these)
103. Brain cells are made of __________.
(Proteins, Fats, Carbohydrates, Lipids)
104. Nerve tissues are made of __________.
(Fats, Proteins, Carbohydrates, Steroids)
105. Fat-soluble vitamins are obtained from __________.
(Carbohydrates, proteins, fats, lipids)
106. Vegetable oils such as peanut oil contain vitamin __________.
(A, B, C, E)
107. Milk fat, butter, cream, and fish liver oil contain vitamin __________.
(A, B, C, A and D)
108. Our balanced diet contains 70 grams per day of __________.
(Carbohydrates, Proteins, Fats, None of these)
109. About 35% of our daily caloric requirements are obtained from __________,
(Carbohydrates, Proteins, Fats, Vitamins)
110. __________ is the term used to reflect the development of any disagreeable odour in the fat or oil.
(Acidity, Basicity, Rancidity, none of these)
111. Two principal chemical reactions responsible for causing rancidity are __________.
(Oxidation and Hydrogenation, Oxidation and Hydrolysis, Hydrolysis and fermentation, Oxidation and Pyrolysis)
112. The reaction of fat with a strong base such as NaOH to produce glycerol and the salt of a fatty acid is used to produce __________.
(Soap, Glucose, Vegetable oil, Gastric Juice)
113. The word enzyme has a __________.
(Greek origin, Latin origin, Roman origin, Arabic origin)
114. In living systems enzymes catalyze reactions at __________°C.
(0, 25, 100, 37)
115. The substance upon which an enzyme acts is known as its __________.
(base, substrate, nutrient, pair)
116. The amount of enzyme, which will catalyze the transformation of one micro-mole of a substrate per minute is termed as __________.
(Substrate, potency, activity, specific activity)
117. Units of enzyme per milligram of proteins are termed as __________.
(activity, potency, turn over, none of these)
118. The number of moles of substrate transformed per mole of enzyme per minute at a definite temperature is called __________.
(Potency, Turn over, Activity, none of these)
119. Enzymes are most commonly named by adding the suffix to the root of the name of the substrate __________.
(ose, ase, ane, ene)
120. Urease acts upon __________.
(Sucrose, Urea, Ammonia, Starch)
121. Sucrose is also called __________.
(invertase, Urea, Renin, Amylase)
122. __________ is an enzyme.
(Sucrose, Sucrase, Maltose, Urea)
123. __________ enzyme was first obtained by grinding pancreatic tissue with glycerol.
(Amylase, Urea, Ascorbic Acid Oxidase, Trypsin)
124. The site of the enzyme, which combines with the substrate, and at which transformation from substrate to products occurs, is called he __________.
(Cellular site, Active site, Vacant site, Complex)
125. The main factors, which effect enzyme activity, are __________.
(concentration, temperture and pH, concentration, temperature, pH and co-enzymes, concentration, temperature, pH, co-enzymes (activators and inhibitors) and radiation, co-enzymes, activators and inhibitors)
126. The majority of enzymes are most active at about __________ °C.
(35, 45, 55, all of these)
127. Many enzymes contain a protein part and a non-protein part. The protein part is called the __________.
(Apoenzyme, Coenzyme, Enzyme, none of these)
128. The non-protein part in enzyme is termed as __________.
(Apoenzyme, coenzyme, substrate, all of these)
129. Examples of co-enzymes are __________.
(Vitamins, Compounds derived from vitamins, Vitamins or compounds derived from vitamins, all of these)
130. In organic substances that tend to increase the activity of an enzyme are called __________.
(activators, Inhibitors, Apoenzymes, coenzymes)
131. Magnesium ion is an inorganic activator for the enzyme __________.
(Trypsin, Carbonic anhydrate, Sucrase, Phosphatase)
132. Zinc ion is an activator for the enzyme __________.
friendsmania.net
(Amulase, Carbonic anhydrase, Renin, Phosphatase)
133. Substances, which tend to decrease the activity of enzyme are called __________.
(Activators, Accelerators, Inhibitors, Retarders)
134. Enzymes are generally inactivated rapidly by exposure to __________.
(Ultraviolet light, b-rays, g-rays, X-rays, all of these)
Chapter 11
Chemical Industries in Pakistan
1. The substances added to the soil to provide one or more nutrient elements essential for plants growth are called __________.
(Growth hormones, Minerals, Fertilizers, Salts)
2. The substances added to the soil in very small amounts (about 6 grams to 200 grams per acre) are called __________.
(Macronutrients, Micronutrients, Fertilizers, none of these)
3. Fertilizers are classified into __________.
(two major categories, three major categories, four major categories, none of these)
4. Natural fertilizers are materials derived from __________.
(plants, animals, algae, all of these)
5. A natural fertilizer provide about __________ kg of nitrogen.
(4.5, 3.2, 2.2, 1.5)
6. A natural fertilizer provides __________ kg of P2O5.
(4.5, 3.2, 2.2, 1.5) A
7. A natural fertilizer provides __________ kg of potash (K2O).
(4.5, 3.2, 2.2, 1.5)
8. The percentage of nitrogen in ammonia is __________%.
(32, 55, 82, 25)
9. The percentage of nitrogen in ammonium Nitrate is __________%.
(32-33.5, 50-55, 80-82, 20-25)
10. The percentage of nitrogen in ammonium sulphate is __________%.
(27, 21, 23, 19)
11. The percentage of sulphur in ammonium sulphate is __________%.
(25, 21, 23, 19)
12. The percentage of nitrogen in Urea is __________%.
(37, 50, 46, 82)
13. Ammonia when used directly as a fertilizer is to be injected about __________ under the surface to keep it from seeping out.
(2 inches, 4 inches, 6 inches, 8 inches)
14. Ammonium nitrate is sold as a mixture with __________.
(Soda Ash, Limestone, Zinc, None of these)
15. The percentage of nitrogen in Diammonium hydrogen phosphate is __________%.
(16, 48, 32, 64)
16. The percentage of P2O5 in diammonium hydrogen phosphate is __________%.
(16, 32, 48, 64)
17. A fertilizer; potassium chloride is sold as __________.
(Muriate of potash, Mixture of potash, Potency of potash, none of these)
18. The percentage of K2O in potassium chloride is __________%.
(60-63, 50-70, 40-80, 30-90)
19. Potassium sulphate with 48% to 52% potash, is made from __________.
(Potassium Phosphate, Potassium Chloride, Potassium Nitrate, none of these)
20. __________ is preferred for horticultural crops and for tobacco and potatoes.
(Potassium chloride, Potassium sulphate, Potassium Nitrate None of these)
21. __________ is used for fruits, vegetables and tobacco.
(Potassium chloride, Potassium sulphate, Potassium Nitrate None of these)
22. Any material, which changes the cleaning effect of water, is called __________.
(Fertilizers, Detergent, Acid none of these)
23. __________ are sodium and potassium salt of long chain fatty acids.
(Soaps, Detergents, Fertilizers, None of these)
24. __________ contain sodium or potassium salts of aryl or alkly sulphonated acids as one of their constituents.
(Soaps, Detergents, Fertilizers, none of these)
25. Soap is a surfactant of the type __________.
(anionic, cationic, nonionic, none of these)
26. __________ is best in its cleaning action.
(Soap, Detergents, Surfactant, None of these)
27. Hydrolytic reaction of fat with caustic soda is known as __________.
(Esterification, Saponification, Acetylation, Carboxylation)
28. Turpentine is obtained from __________.
(Oak tree, Pine tree, Birch tree, Lemon tree)
29. __________ surfactants perform well over a wide range of water hardness and pH.
(Anionic, Cationic, Nonionic, none of these)
30. Fats and oils are __________.
(Acids, alcohols, salts, none of these)
31. Washing soap can be prepared by saponification with alkali of __________ of the following oil.
(Rose oil, Paraffin oil, Groundnut oil, Kerosene oil)
32. Commercial detergents contain mainly __________.
(RCOON, RONa, RSNa, ROSO3Na)
33. Sodium tripolyphosphate is __________.
(a surfactant, a builder, a auxiliary agent, none of these)
34. In glass or vitreous state solid the atoms are arranged in __________.
(Regular fashion, Random fashion, Linear fashion, none of these)
35. Glass was first made by about __________.
(40BC, 400BC, 4000BC, none of these)
36. The number of glass products now manufactured is __________.
(25,000, 50,000, 75,000, none of these)
37. The substance that can form the glassy, non-crystalline structure is called __________.
(Formers, Fluxes or modifiers, Stabilizers, none of these)
38. The principle former of almost all glasses is __________.
((SiO2)n, (SiO3)n, (SiO2)X, none of these)
39. Chemical compounds, which are added to reduce the reactivity of glass, are called __________.
(Formers, Modifiers, Stabilizers, none of these)
40. __________ is used as stabilizer.
(Ca2O, SiO2, Na2O, none of these)
41. In glass making the whole combination of ingredients is called a __________.
(Gangue, Batch, Mixture, none of these)
42. The melting of nearly all glass is done in a continuous tank furnace, which operates steadily over periods of up to __________.
(a day, a month, a year, none of these)
43. __________ is a heat-treatment cycle that prevents glass from harmful stress.
(Forming, Annealing, Batching, none of these)
44. __________ is used for Annealing.
(Klin, Batch, Converter, Oven)
45. The main constituents of __________ are boron oxide and silica.
(Pyrex glass, Soda-lime glass, Low silica glass, Fibrous glass)
46. In Pakistan how many units are involved in the production of glass __________.
(20, 25, >25, none of these)
47. In Pakistan the total production of glass is over __________ tons per year.
(800, 8000, 80,000, none of these)
48. Asbestos is a __________.
(Mineral fibre, Animal fibre, Vegetable fibre, none of these)
49. __________ is the fibre in which the basic polymer (fibre forming substance) is a long chain composed of least 85% by weight of Acrylonitrile units.
(Acrylic Fibre, Modacrylic fibre, Polyster fibre, Rayon Fibre)
50. The fibre, which has less than 85% but more than 35% proportion by weight, of acrylonitrile units is called __________.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
51. __________ is the fibre in which the fibre-forming substance is a long chain synthetic polymer composed of at least 85% by weight of an ester of a dihydric alcohol and terephthalic acid.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
52. __________ is a fibre composed of regenerated cellulose in which substituents have replaced nor more than 15% of the hydrogen of the hydroxyl group.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
53. __________ compound contains cellulose acetate as fibre forming substance.
(increases, decreases, remains constnt, none of these)
44. The electropositive elements form __________.
(acidic oxides, basic oxides, neutral oxides, none of these)
45. __________ of the following elements has the lowest first ionization energy.
(Na, F, I, Cs)
46. The electronegative elements form __________.
(Acidic oxides, Basic oxides, Neutral oxides, none of these)
47. __________ is the most volatile compound.
(HI, HCl, HBr, HF)
48. The ionization energy of nitrogen is more than oxygen because of __________.
(more attraction of electrons by the nucleus, more peneration effect, the extra stability of half filled p-orbitals, the size of nitrogen atom is smaller)
49. The elements of group IIA are called __________.
(Metals, Non-metals, Alkaline earth metals, Transition elements)
50. __________ ion has the largest radius.
(Al+3, Cl-, F-, O-2)
51. __________ atom has the smallest size.
(C, F, Li, Rb)
52. __________ of the following has highest first ionization energy.
(Br, Cl, F, I)
53. The most electropositive among the following elements is __________.
(Fe, Na, Cs, Pb)
Chapter 2
Hydrogen
1. Large amounts of atomic hydrogen are present in the atmosphere of __________.
(Earth, Sun, Moon, none of these)
2. Hydrogen atom contains __________ electrons.
(1, 2, 3, 4)
3. During the electrolysis of water hydrogen is liberated at the __________.
(Anode, Cathode, Diode, none of these)
4. The atomic weight of hydrogen is __________.
(1.00, 1.008, 1.08, 1.800)
5. In nature hydrogen exists in __________.
(Gaseous state, Solid state, Liquid state, Plasma state)
6. __________ is the lightest gas.
(Nitrogen, Helium, Oxygen, Hydrogen)
7. Alkali metals do not exist in __________.
(Monoatomic, Diatomic, Triatomic, none of these)
8. Hydrogen generally combines with other elements to form __________.
(Ionic bond, Covalent bond, Polar bond, none of these)
9. Hydrogen may be readily prepared by the action of water on __________.
(Fe, HCl, Zn, Na)
10. In organic compounds, __________ element is found in close association with hydrogen.
(C, N, O, none of these)
11. Ionic hydrides are usually __________.
(liquids at room temperature, good reducing agents, good electrical conductors in solid state, Easily reduced)
12. The atoms of the same element, which have the same atomic number but different mass numbers, are called __________.
(Isotopes, Actanides, Isobars, none of these)
13. The difference in atomic weights or mass numbers of the atoms of the same element is due to __________.
(Different number of electrons in them, different number of protons in them, different number of neutrons in them, none of these)
14. A tritium nucleus has __________.
(one proton and two electrons, one proton and two neutrons, one neutrons and two protons, one proton and three neutrons)
15. Physical properties of elements depend upon the number of __________.
(Protons in the nucleus, neutrons in the nucleus, electrons in the valence shell, both protons and neutrons in the nucleus)
16. Chemical properties of elements depend upon the number of __________.
(electrons in the valence shell, protons in the nucleus, neutrons in the nucleus, protons and neutrons in the nucleus)
17. Chemical properties of elements depend upon their __________.
(Atomic number, Atomic weight, volume, none of these)
18. The hydronium ion is a/an __________.
(ion with formula H2O+, ion with the formula H3O+, free radical rather than an ion, ion formed by removal of H- form a water molecules)
19. Hydrogen is an important constituent of __________.
(Water, Petroleum, Natural gas, all of these)
20. When steam is passed over red hot coke at 1000°C, a mixture of carbon monoxide and hydrogen gas is produced. It is known as __________.
(Heavy water, Water gas, Phosgen gas, none of these)
21. The most suitable process for the separation of CO from water gas is __________.
(Bosch Proces, Lane’s Process, Electrolysis of water, None of these)
22. When steam is passed over iron at 500°C, magnetic oxide and hydrogen gas is produced. This is called __________.
(Bosch Process, Lane’s Process, Electrolysis, All of these)
23. The presence of an acid or base renders water __________.
(good conductor of electricity, poor conductor of electricity, very bad conductor of electricity, all of these)
24. The process of loss of oxygen from a substance or addition of hydrogen is called __________.
(Oxidation, Reduction, Hydrogenation, None of these)
25. Hydrogen is a very good __________.
(Reducing agent, Oxidizing agent, Reducing agent as well as oxidizing agent, none of these)
26. Lowering of oxidation state of a metal is termed s __________.
(Oxidation, Reduction, Hydrogenation, All of these)
27. The process of addition of hydrogen (H2) to a molecule is called __________.
(Oxidation, Reduction, Hydrogenation, all of these)
28. Formation of vegetable ghee from vegetable oil is an example of __________.
(Oxidation, Reduction, Hydrogenation, all of these)
29. Ethylene can be hydrogenated to __________ under pressure at about 300°C, when double bond is changed to single compounds.
(Methane, Ethane, Ethyne, None of these)
30. Hydrogen reacts with halogens to give __________.
(Hydrogen halides, hydrogen hydrides, hydrogen sulphides, All of these)
31. Hydrogen is used in the manufacture of __________.
(Fertilizers, CO2, O2, None of these)
32. Hydrogen at the time of its generation during chemical reaction is in the form of atomic state and is called __________.
(Ionic Hydrogen, Nascent hydrogen, atomic hydrogen, none of these)
33. Hydrogen molecule consists of two atoms linked together by a strong __________.
(Ionic bond, Covalent bond, Hydrogen bonding, None of these)
34. Nascent hydrogen is used in the reduction of __________.
(Ionic compounds, Organic compounds, Inorganic compounds, none of these)
35. The compounds formed between two elements are called __________.
(Hydrides compounds, Binary compounds, Tertiary compounds, None of these)
36. Hydrogen reacts with some elements to form binary compounds called __________.
(Halides, Hydrides, Oxides, all of these)
37. The hydrides formed by the transfer of electrons from electropositive metals to hydrogen are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
38. NaH is an example of __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
39. Ionic hydrides ionize to produce __________.
(H-ion, OH-ion, H+ion, all of these)
40. The hydrides, which are good conductors of electricity in the fused state, are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides)
41. Covalent hydrides generally exist in __________.
(Solid state, Liquid state, Gaseous state, all of these)
42. Covalent hydrides are prepared by the direct action of __________.
(metals with hydrogen, non-metals with hydrogen, transition elements with hydroge, none of these)
43. Hydrides, which are non-stoichimetric in nature, are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
44. The law of chemical combination is not obeyed by __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
45. Electron deficient hydrides are called __________.
(Ionic hydrides, covalent hydrides, Complex hydrides, Interstitial hydrides
46. Hydrogen occurs in __________.
(One isotopic forms, two isotopic forms, three isotopic forms, four isotopic forms)
47. Atomic hydrogen is __________.
(More reactive than molecular hydrogen, less reactive than molecular hydrogen, very less reactive than molecular hydrogen, all of these)
48. The process of addition of hydrogen to a molecule is called __________.
(Halogenation, Hydrogention, Sulphonation, Reduction)
Chapter 3
S - Block Elements
1. Out of all the elements of group IA, the highest atomic number is for __________.
(Na, Cs, Rb, K)
2. Out of all the elements of group IA, the highest melting and boiling point is for __________.
(Li, Na, Rb, K)
3. __________ of the following elements has highest ionization potential.
(K, Rb, Cs, Li)
4. Out of all the elements of group IA, the highest heat of hydration is for __________.
(Li, Na, K, Rb)
5. __________ of the elements has highest melting and boiling point.
(Be, Ca, Mg, Ba)
6. __________ of the following elements have highest oxidation potential.
(Na, Li, Rb, K)
7. Out of all the elements of group IIA, the highest density at 20°C is for __________.
8. Out of all the following elements of group IIA, the highest atomic number is for __________.
(Be, Ba, ca, Sr)
9. The alkali metals possesses __________ electrons in their outermost orbitals.
(1, 2, 3, 4)
10. Out of all the elements of group IIA, the highest heat of hydration is for __________.
(Be, Ba, Ca, Mg)
11. __________ of the elements has highest ionic radius.
(Be, Ba, Sr, Ca)
12. Out of all the elements of group IA, the highest heat of hydration is for __________.
(Li, Na, K, Cs)
13. Of all the group II elements, the highest oxidation potential is for __________.
(Li, Be, Ba, Ra)
14. Sodium is not observed in +2 Oxidation State because of its __________.
(high first ionization potential, high second oxidation potential, high ionic radius, high electronegativity)
15. The metallic lustre of sodium is explained by the presence of __________.
(Na+ ions, conduction electrons, free protons, a body centred cubic lattice)
16. __________ of the following substances is manufactured by electrolysis of NaCl solution.
(NaOH, Na2ClO3, NaClO3, Na)
17. When NaCl is dissolved in water, the sodium ions become __________.
(Oxidized, Reduced, Hydrolyzed, Hydrated)
18. NaCl imparts a golden yellow colour to the Bunsen flame. This can be interpreted due to __________.
(Low ionization potential of sodium, Photosensitivity of sodium, Sublimation of metallic sodium to give yellow colour, Emission of excess energy absorbed as a radiation in the visible region)
19. The alkaline earth metals possess __________ electron or electrons in their outermost orbitals.
20. Alkali metals form __________.
(Ionic bond, covalent bond, non-polar, Vander waal’s forces)
21. Sodium salts constitute __________% of earth’s crust.
(2.40, 2.35, 2.30, 2.25)
22. Potassium salts constitute __________% of the earth’s crust.
(2.40, 2.35, 2.30, 2.25)
23. Alkaline earth metals occur in nature in __________.
(free state, combined state, both free and combined state, none of these)
24. In general alkali metals act as __________.
(Reducing agents, Oxidizing agents, Both reducing and oxidizing agents, none of these)
25. All alkaline metals except __________ are white in colour.
(Be, Mg, Ca, None of these)
26. In the alkali metal series __________ of the following is most reactive.
(Li, Na, K, Rb)
27. In the alkali metal series, Cesium is the most reactive metal because __________.
(its incomplete shell is nearest to nucleus, the valence electron has a larger orbit than the orbit of the valence electron of any of the others, it exerts considerable Beautiful force on the valence electrons, it is a heavier metal)
28. Alkali metals are __________.
(lighter than water, heavier than water, enlarged than water , all of these)
29. __________ does not belong to alkali metals.
(Li, Na, Rb, K)
30. A graphite anode is used in Down’s cell for the production of sodium because __________.
(It does not react with sodium, it does not react with chorine, it is easy to fashion in circular form, it floats on the fused sodium chloride)
31. __________ is a reducing agent and a constituent of a gun powder.
(KNO3, C, CaCO3, Na)
32. Alkaline earth metals form __________ carbides on heating with carbon.
(Stable, Unstable, soluble, none of these)
33. Except lithium, all alkali metal hydroxides are strongly __________.
(acidic in nature, basic in nature, neutral in nature, none of these)
34. Alkaline earth metal carbonates, sulphates and phosphates are __________.
(soluble in water, insoluble in water, sometimes soluble and sometimes insoluble in water, none of these)
35. Alkali metal carbonates, sulphates and phosphates are __________ in water with the exception of Li2CO3 and Li3PO4.
(soluble, insoluble, Both soluble and insoluble, none of these)
36. LiCl is soluble in organic solvents while NaCl is not. This is because __________.
(Lattice energy of NaCl is less than LiCl, Li+ has higher value of hydration energy than that of Na+, LiCl is more covalent in nature than NaCl, Li+ has lower value of hydration energy than Na+)
37. When burnt in air, Lithium forms __________.
(Normal oxide, Peroxide, Super oxide, none of these)
38. The chlorides of alkali metals and alkaline earth metals are generally __________.
(Ionic, Covalent, non polar, vander waal’s forces)
39. Sodium is a __________.
(good conductor of electricity, poor conductor of electricity, bad conductor of electricity, none of these)
40. Sodium reacts vigorously with oxygen on heating to form __________.
(Sodium oxide, Sodium peroxide, sodium superoxide, all of these)
41. Sodium is very reactive with water. Hence due to its high reactivity with water, it is stored in __________.
(Alcohol, Kerosine oil, Benzene, all of these)
42. Sodium reacts vigorously with water, liberating __________.
(Oxygen, hydrogen, Carbonoxide, Neon)
43. Sodium is a powerful __________.
(Reducing agent, oxidizing agent, bleaching agent, all of these)
44. __________ is used s a reducing agent in the preparation of such metals as titanium and zicronium from their chlorides or oxides.
(Mg, Na, Cu, Ag)
45. __________ is used in the synthesis of rubber.
(Mg, Cu, Na, Fe)
46. __________ reducing action is used in the manufacture of certain dyes and drugs.
(Na, Mg, Cu, Ca)
47. __________ is used often in highway lamps as filaments to produce yellow light.
(Na, Tungston, Mg, Fe)
48. Purification of sodium chloride is accomplished by __________.
(Sublimation, Crystallization, Hydrogenation, Melting)
49. Ice and sodium chloride form a freezing mixture, which is used in __________.
(Refregeration, Preserving fish, Sublimation, None of these)
50. Sodium bicarbonate is commonly called __________.
(Soda Ash, Baking soda, Caustic soda, none of these)
51. Soap is often composed of __________.
(sodium carbonate, calcium carbonate, rubidium carbonate, sodium stearate)
52. Solvay’s process is also called __________.
(Haber’s Proess, Ammonia Soda Process, Washing Soda Process, Down’s Process)
53. __________ is a stronger base.
(NaOH, KOH, LiOH, HCl)
54. Na2CO3 is marketed as __________.
(Soda ash, baking soda, caustic soda, none of these)
55. When a solution of sodium carbonate is evaporated, Na2CO3.10H2O crystallizes out t room temperature and marketed as __________.
(Soda ash, baking soda, caustic soda, washing soda)
56. By the action of aqueous NaOH on aluminium, __________ is produced.
(H2, CO2, H2O, O2)
57. __________ is used for weighing cotton cloth.
(Gypsum, Soda ash, Magnesium Sulphate, Washing soda)
Chapter 4
P - Block Elements
1. __________ of the following is non-metal.
(Boron, Aluminium, Indium, Thallium)
2. __________ of the following was isolated by Davy in 1807 by electrolysis of moist boric acid.
(Boron, Indium, Aluminium, Gallium)
3. __________ of the following is chemically inert.
(Boron, Indium, Aluminium, Gallium)
4. __________ is not the member of group IIIA.
(B, In, C, Al)
5. The oxides of Boron are __________ in nature.
(Acidic, Basic, Neutral, None of these)
6. __________ forms the most acidic oxide.
(B, Al, Ga, In)
7. Boron bursts into flame at __________.
(600°C, 700°C, 800°C, None of these)
8. B3+ cannot exist in aqueous solution because of its __________.
(Strong reducing ability, large size and small charge, small size and large charge, strong oxidizing ability)
9. Orthoboric acid on heating to about 100°C looses a water molecule to form __________.
(Metaboric acid, Pyroboric Acid, Metaboric and Pyroboric acid, none of these)
10. The reduction of metal oxides is sometimes accomplished by using aluminium in the __________.
(Goldshmidt’s reaction, Silberchmdit’s reaction, Baeyer’s reaction, Zilch’s reaction)
11. Baeyer’s Process is used for the purification of __________.
(Alum stone, Cryolite, Bauxite, none of these)
12. Hall’s Process is based on electrolysis of __________.
(Alumina, Gypsum, Borax, none of these)
13. __________ is a better conductor of heat.
(Fe, Sn, Al, none of these)
14. Al2O3 formation involves evolution of a larger quantity of heat, which makes its use in __________.
(Deoxidizer, confectionary, indoor photography, thermite welding)
15. A mixture of iron oxide and aluminium is called __________.
(Thermite, Bauxite, Alum, none of these)
16. Aluminium is used in __________.
(X-ray welding, Spot welding, Thermite welding, none of these)
17. __________ metal is used in photo-flash bulbs.
(Ca, Na, W, Al)
18. The alloy of aluminium, which contains small quantities of manganese, copper and magnesium, is called __________.
(duralumin, Magnalium, Alnico, none of these)
19. The alloy of aluminium with small percentage of magnesium is called __________.
(Duralumin, Magnalium, Alnico, none of these)
20. The aluminium which contains 20% nickel, 20% aluminium, 50% iron and 10% cobalt is called __________.
(Duralumin, Magnalium, Alnico, none of these)
21. A magnet made of __________ will lift approximately 4000 times of its own weight of iron.
(Duralumin, Magnalium, Alnico, none of these)
22. An alloy of aluminium made by alloying 5-15% aluminium and has a golden lustre is called __________.
(duralumin, Magnalium, Aluminium Bronze, none of these)
23. All the alums crystallize to yield __________.
(Octahedral crystal, Tetrahedral crystal, Trigonal crystal, Linear crystal)
24. The process of permanent dyeing is called __________.
(Mordanting, Painting, Calination, none of these)
25. The solvent used in the extraction of aluminium from its ore is __________.
(Cryolite, Bauxite, Molten sodium chloride, Water)
26. The group IV-A of the periodic table consists of __________ elements.
(three, four, five, six)
27. In group IV-A the metallic character down the group __________.
(Increases, Decreases, remains constant, none of these)
28. __________ does not contain aluminium.
(Felsper, Cryolite, Kaoline, Anhydrite)
29. Carbon differs from other members of its group due to the absence of __________ electrons.
(s, p, d, none of these)
30. Elements, which exist in two or more physical or molecular forms, are called __________.
(Isotopes, Allotropes, Isobars, none of these)
31. Out of the following elements of group IV A of the periodic table the higher density is for the element __________.
(C, Si, Ge, Pb)
32. Diamond is a __________ conductor of electricity and heat.
(Poor, Good, None, none of these)
33. Out of all the elements of group IV the higher density is for __________.
(C, Si, Ge, Pb)
34. __________ is used as a lubricant for machinery and also as a moderator in nuclear reactors.
(Diamond, Graphite, Epsom, Gypsum)
35. Highest melting and boiling point is for __________.
(C, Ge, Si, Pb)
36. PbO behaves as a/an __________.
(Amphoteric oxide, basic oxide, super oxide, sub oxide)
37. White lead is prepared by __________.
(Dutch process, Solvay’s Process, Down’s Process, none of these)
38. __________ member of the group V-A show several oxidation states such as –1, +2, +3, +4 and +5.
(P, As, Sb, N)
39. __________ member of the group V-A forms multiple bonds.
(P, Bi, As, N)
40. __________ member of group V-A does not show allotropy.
(P, Sb, N, As)
41. In __________ solution glass is soluble.
(HNO3, HCl, HF, H2CO3)
42. On industrial scale Nitric acid is prepared by __________.
(Dutch Process, Birkland-Eyde’s Process, Solvay’s Process, Down’s Process)
43. In Ostwald’s Process the substance used to oxide ammonia is __________.
(Zn, Pt, CO, none of these)
44. Copper reacts with dilute nitric acid to form __________.
(Nitric oxide, nitrogen peroxide, nitrous oxide, none of these)
45. Nitric acid is a strong __________.
(reducing agent, bleaching agent, oxidizing agent, none of these)
46. A mixture consisting of one volume of concentrated HNO3 and three volumes of concentrated HCl is called __________.
(Aqua regia, Meta stannic acid, Alum, Sandhur)
47. Lead tertraethyle is used as __________.
(Fire extinguisher, Pain Killer, Mosquito repellent, Petroleum Additive)
48. Nitric acid is used in the manufacture of __________.
(Cellulose, Varnishes, T.N.T, all of these)
49. __________ allotropic form of coal is hard.
(Peat, Lignite, Anthracite, Graphite)
50. __________ molecule is paramagnetic nature.
(O, S, Se, Po)
51. __________ element edhibits the largest number of allotropic forms amongst the elements.
52. __________ element is the most abundant element in earth’s crust.
(Ca, Si, C, O)
53. There are __________ rings in unit cell of Rhombic sulphur.
(12, 16, 20, 24)
54. Graphite is used in nuclear reactor as __________.
(A Lurbicant, A fuel, for lining the inside of reactor as an insulator, for reducing the velocity of neutrons)
55. In its unit cell, monoclinic sulphur possesses how many S8 rings.
(12, 6, 3, 0)
56. H2S is a good __________.
(reducing agent, oxidizing agent, bleaching agent, none of these)
57. In the aqueous solution H2S ionizes to produce __________ ions and behaves as a weak acid.
(H+, H-, OH-, none of these)
58. H2S reduces halogens to __________.
(hidrides, halides, halogens, none of these)
59. By __________ process the H2SO4 produced is pure and can be produced of any desired strength.
(Lead Chamber Process, Contact Process, Down’s Cell, none of these)
60. __________ gas is responsible for rising of bread.
(CO, CO2, NH3, O2)
61. At what temperature H2SO4 completely dissociates into sulphur trioxide and water.
(416°C, 516°C, 616°C, 716°C)
62. Concentrated sulphuric acid acts as a __________.
(Reducing agent, Oxidizing agent, Dehydrating agent, None of these)
63. __________ charcoal is used to decolourise brown sugar solution.
(Wood, Coconut, Animal, Sugar)
64. In the sale of diamonds the unit of weight is carat. One cart is equal to __________.
(100mg, 200mg, 300mg, 400mg)
65. Hot concentrated sulphuric acid acts as an __________ usually itself reduced to sulphur dioxide.
(Dehyrating, Oxidizing, Reducing, none of these)
66. __________ are the two elements that find wide application in transistor industry.
(Silicon and Germinium, Carbon and Platinium, Iridium and Germanium, Tungsten and Platinium)
67. In the manufactur of certain explosives such as nitroglycerine, trinitrotoluene and gun-cotton etc. Sulphuric acid is used as a __________.
(Oxidizing agent, Reducing agent, Dehydrating agent, none of these)
68. __________ prepared chlorine in 1774, by the action of hydrochloric acid on manganese dioxide.
(Cavendish, C.W. Scheele, Sir Humphry Davy, Lane)
69. __________ suggested the name chlorine for the gas produced by the action of hydrochloric acid on manganese dioxide.
(Sir Humphry Davy, C.W. Scheele, Cavendish, none of these)
70. Chlorine is obtained by reacting concentrated HCl with __________ agent, such as MnO2, KClO3, KMnO4.
(Reducing, oxidizing, dehydrating, none of these)
71. Electrolysis of Brine produces __________.
(Chlorine, Hydrogen, H2S, Nitrogen)
72. The process based on the oxidation of hydrochloric acid with oxygen is __________.
(Nelson’s Cell, Contact Process, Down’s Process, Deacon’s Process)
73. __________ process is used for the production of chlorine gas.
(Deacon’s, Contact, Solvay’s, Electrolysis of water)
74. Chlorine gas is __________ in colour.
(Yellow, Greenish Yellow, Violet, Blue)
75. __________ produces inflammation of the nose and throat when breathed in considerable quantities.
(Nitrogen, Carbon dioxide, Chlorine, Hydrogen Sulphide)
76. To kill bacterial, molst of the drinking water is treated with __________.
(Nitrogen, Carbon dioxide, Chlorine, Hydrogen Sulphide)
77. Chlorine is used in the preparation of poisonous gases of warfare, such as __________.
(COCl2, H2S, HCl, none of these)
78. In phosphorus oxide the number of oxygen atoms bonded to each phosphorus atom is __________.
(1, 2, 3, 4)
79. Of the following elements the only one which does not exhibit allotropy is __________.
(P, As, Sb, Bi)
80. Phosgene is the common name of __________.
(Carbon dioxide and Phosphine, Phosphoryle chloride, Carbonyle Chloride, Carbon Tetrachloride)
81. Out of all the elements of group VI A, the highest melting and boiling point is for __________.
(Te, Se, S, Pb)
82. In group VIA highest electronegativity is for __________.
(S, O, Pb, Se)
83. Large deposits of sulphur in nature are found as __________.
(Sulphuric acid, hydrochloric acid, free sulphur, none of these)
84. On the basis of available data of the structure of monoclinic sulphur, it probably consists of __________ chains.
(S6, S2, S4, S8)
85. Rhombic sulphur consists of __________.
(S8 chains, S2 chains, S4 rings, S8 rings)
86. Pure sulphuric acid is a solid compound which __________.
(Is always colloidal, slowly decomposes to form SO2, Seves as a useful source for H2S, has never been observed)
87. The form of sulphur, which is stable at room temperature and normal atmospheric pressure, is __________.
(orthorhombic, hexagonal, mono clinic, amorphous)
88. When H2S gas is dissolved in aqua regia, the function of HCl in the mixture is to __________.
(oxidize the sulphur, oxidize the mercury, complex the sulphur, complex the mercury)
89. When liquid sulphur at one atmosphere pressure is very slowly cooled, unless super cooling occurs, the first solid to appear is __________.
(monoclinic sulphur, Rhombic sulphur, Hexagonal sulphur, metallic sulphur)
90. The synthesis of ethers from alcohol depends on the fact that sulphuric acid is a good __________.
(oxidizing agent, reducing agent, complexing agent, dehydrating agent)
91. __________ of the following has the highest catenation capability.
(Oxygen, Sulphur, Selenium, Tellurium)
92. the halogen with the highest ionization potential is __________.
(F, Cl, I, At)
93. The halide ion with the highest hydration energy is __________.
(F-, Cl-, I-, At-)
94. Hydrofluoride acid is __________.
(a powerful oxidizing agent, a weak acid, a strong acid, a good reducing agent)
95. __________ of the following is most powerful oxidizing agent.
(F2, Cl2, Br2, I2)
96. __________ of the following exhibits the largest electrical conductivity in the liquid state.
(F2, Cl2, Br2, I2)
97. __________ of the following exhibits the highest bond energy.
(F2, Cl2, Br2, I2)
98. __________ does not form its oxy acids.
(F2, Cl2, Br2, I2)
99. The colour of I2 solution can be discharged by shaking a aqueous solution of __________.
(Sulphur dioxide, sodium thiosulphate, sodium sulphite, sodium sulphate)
100. Bleaching powder is obtained by the interaction of Cl2 and __________.
(a dilute solution of Ca(OH)2, conc. Solution of Ca(OH)2, dry CaO, dry slaked lime)
Chapter 5
Transition Elements
1. Transition elements are those in which __________ orbitals are in the process of completion.
(d, f, s, d or f)
2. Transition elements are located between __________ elements in the periodic table.
(s and p block, s and f block, d and p block, none of these)
3. Out of total 110 elements known, there are more than __________ transition elements.
(40, 50, 60, 70)
4. Elements in which d-orbitals are in the process of completion are called __________ elements.
(outer transtion, inner transition, non-transition, none of these)
5. __________ of the following is transition element.
(Sr, Sn, Cr, B)
6. __________ of the following elements is not included in the list of transition elements.
(Ca, Cu, Cr, CO)
7. Due to the addition of electrons in inner f-robitals atomic and ionic radii or f-block elements have a regular trend. This is called __________.
(Contraction, Lanthanide contraction, actanide, contraction, none of these)
8. The transition elements usually have very __________ melting and boiling points.
(low, high, intermediate, none of these)
9. Transition elements show a tendency of __________.
(high reactivity, less reactivity, very high reactivity, none of these)
10. Finely divided iron is used in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Contact Process)
11. __________ reagent can be used to identify Cu2+ ion.
(Nitric acid, Sulphuric acid, Sodium hydroxide, Potassium chromate)
12. Vanadium pentaoxide is used in __________.
(Haber Process, Oxidation of sulphur dioxide to sulphur trioxide, oxidation of ammonia to nitric oxide, Contact Process)
13. __________ is the important ore of copper.
(Malachite, Bauxite, Blue Vitriol, Alumina)
14. Copper is used in __________.
(Haber Process, Oxidation of ethyl alcohol to acetaldehyde, oxidation of ammonia to nitric oxide, Contact Process)
15. Bessemer converters are used to get __________.
(Aluminium, Copper, Steel, Sodium)
16. Titanium is used as catalyst in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Polymerization of ethyle into polyethylene)
17. Platinium or Palladium is used as catalyst in __________.
(Haber Process, Catalytic Hydrogenation, Oxidation of ammonia to nitric oxide, Contact Process)
18. __________ of the following does not belong to d-block elements.
(Chromium, Cobalt, Silicon, Copper)
19. Compounds attracted into a magnetic field are called __________.
(Magnets, Paramagnets, Dimagnets, none of these)
20. Transition metal compounds, which show paramagnetism, have __________.
(unpaired electrons, paird electrons, unpaired protons, paired protons)
21. A substance, which have even number of electrons and have paired spin is called __________.
(Ferromagnetic, Paramagnetic, Dimagnetic, none of these)
22. Magnetic movement is measured with help of __________.
(Guoy’s balance, Spring balance, Physical balance, Cavendish Appratus)
23. __________ property provides information about the presence of unpaired electrons in an atom or ion.
(Dipole moment, Magnetic moment, torque, none of these)
24. By measuring the magnetic moment values we can measure __________.
(Nature of the transition metal compound, oxidation state of the transition metal, both nature and oxidation state of transition metal compound, none of these)
25. Transition elements show variable valencies because of the involvement of the d-electrons in addition to __________.
(p-electrons, f-electrons, d-electrons, e-electrons)
26. The empty spaces between atoms of transition metals in their crystal lattices are called __________.
(Vacant spaces, valence spaces, interstices, none of these)
27. The formation of non-stoichiometric compounds is due to the defects in solid structure and __________.
(Variabel valency of transition elemennts, even number of electrons, even number of protons, unpaired electrons)
28. Interstitial compounds have __________ formula.
(definite, half, indefinite, no)
29. Strong paramegnetism is called __________.
(dimagnetism, ferromagnetism, both dimagnetism and ferromagnetism, none of these)
30. When a number of molecules or negatively charged ions combine with a central d-block atom or ion to form complex ion or molecule, __________ is formed.
(a co-ordinate compound, interstitial compound, di-atomic compound, none of these)
31. In coordinate bonding the molecules or ions, which bond onto the central metal ion or atom, are called __________.
(actanides, Lanthanides, Ligands, none of these)
32. Ligands are __________.
(electron pair donors, electron pair acceptros, neutral, none of these)
33. [Ni(CN)4]2- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
34. [Cu(NH3)4]2+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
35. MnO4- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
36. CrO42- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
37. [Cu(CN)4]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
38. [Zn(NH3)4]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
39. [Fe(CN)6]3- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
40. [Fe(CN)6]4- is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
41. [Ni(NH3)6]2+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
42. [Co(NH3)6]3+ is an example of __________.
(Squre planar, tetrahedral complexes, octahedral complexes, none of these)
43. In the system of naming complex coordinate compounds cations are named __________ anions.
(after, beforem, inbetween, none of these)
44. The names of __________ are usually unchanged.
(anionic ligands, cationic ligands, neutral ligands, none of these)
45. NH3 is an example of __________ ligand.
(anionic, cationic, neutral, none of these)
46. H2O is an example of __________ ligand.
(anionic, cationic, neutral, none of these)
47. The suffix “ate” at the end of the name of the coordinate complex ion represents a/an __________.
(cation, anion, cathode, anode)
48. A mixture of iron sulphide and copper sulphide is called __________.
(gangue, matte, matter, residue)
49. Sulphide ore is concentrated by __________.
(Froth floatation Process, Dutch Process, Bessemerization, none of these)
50. __________ does not copper.
(Carborundum, Azurite, Blue Vitriol, Malachite)
51. Utensils used to carry out fermentation are made of __________.
(Cu, Fe, Al, Ca)
52. An alloy of copper, which contains 80% copper and 20% zinc, is called __________.
(Brass, Bronze, Bell metal, none of these)
53. Copper sulphate reacts with solution of potassium iodide giving __________.
(sulphur dioxide, iodine, copper oxide, potassium oxide)
54. An alloy of copper, which contains 90% Cu and 10% Sn is called __________.
(Bronze, Brass, Bell Metal, all of these)
55. An alloy of copper, which contains 80% Cu and 20% Sn is called __________.
(Bronze, Brass, Bell metal, all of these)
56. The substance attracted by magnetic field is known as __________.
(diamagnetic, paramagnetic, antimagnetic, all of these)
57. Copper sulphate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
58. Silver nitrate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
59. Stainless steel is __________.
(a mixture, a compound, an element, all of these)
60. Potassium dichromate is commonly called __________.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
61. Manganese differs from most other transition elements because it reacts with __________.
(oxygen, water, sulphur, iodine)
62. __________ of the following elements can be included in the category of transition elements.
(Cu, Al, Ar, At)
63. Potassium ferrocyanide is a __________.
(normal salt, mixed salt, double salt, complex salt)
64. __________ of the following combination is included in the Iron triad of elements.
(Pd and Pt, Mn and Hg, Co and Ni, V and Ti)
65. __________ is a blue crystalline solid which is freely soluble in water.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
66. __________ is an orange crystalline solid which is freely soluble in water.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
67. __________ is a yellow crystalline solid which is freely soluble in water.
(Nila Thotha, K2CrO4, Surkh Kahi, none of these)
68. __________ is a colourless crystalline solid.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
69. __________ is used as fungicide and germicide.
(Nila Thotha, Lunar Caustic, Surkh Kahi, none of these)
70. Ferric oxide is __________.
(a basic anhydride, an acid anhydride, an amphoteric anhydride, green in colour)
71. Potassium dichromate is a strong __________.
(reducing agent, oxidizing agent, dehydrating agent, all of these)
72. The densest element is __________.
(Pb, Hg, Pt, Os)
73. The most strongly ferromagnetic element is __________.
(Fe, Co, Ni, Os)
74. Alloying of metals serves to inhibit __________.
(Corrosion, Froth Floatation, Erossion, None of these)
75. Mechanical strains can be removed by __________.
(heat treatment, polishing the metal surface, both heat treatment and polishing the metals surface, none of these)
76. __________ has the lowest density.
(Cu, Ni, Sc, Zn)
77. Galvanizing is done by dipping clean iron sheet in a zinc chloride bath and __________.
(heating, rusting, froth floatation, alloying)
78. There are two well known theories to explain the phenomenon of corrosion namely __________.
(Acid theory, Electromechanical theory, electrochemical theory, acid and electromechanical theory)
79. __________ one of the following metals exists in liquid form.
(Sc, Y, La, Hg)
80. The process of depositing a thin layer of tin on base metals to protect them from corrosion is called __________.
(Exposure, tin plating, Fixing, none of these)
81. The most strongly ferromagnetic element is __________.
(Fe, Ni, S, C)
82. The property of a substance which permits it being drawn into wire is called __________.
(softness, Ductility, Brittleness, Hardness)
83. One of the constituent of German silver is __________.
(Ag, Cu, Mg, Al)
84. When potassium permanganate is added to a saturated aqueous solution of potassium hydroxide, __________ gas is evolved.
(Hydrogen, Oxygen, Carbon dioxide, none of these)
85. __________ reagent can be used to identify nickle ion.
(Resorcinol, Dimethyl glyoxime, Dimethyl Benzidine, Potassium Ferrocyanide)
86. __________ of the following is the transition element.
(Sr, Sn, Cr, Fe)
87. Bessemer converters are used to get __________.
(Aluminium, copper, steel, none of these)
88. __________ is not the ore of copper.
(Blue vitriol, Cuprite, Chalcocite, Steel)
89. __________ of the following elements is not included in the list of transition elements.
(Ca, Cu, Cr, Co)
90. __________ one of the following does not belong to d-block elements.
(Chromium, Silicon, Cobalt, Nickel)
Chapter 6
Organic Chemistry
1. The branch of chemistry which deals with the study of compounds containing carbon as a essential element is called __________.
(Organic chemistry, In organic chemistry, Physical chemistry, all of these)
2. The first organic compound synthesized in the laboratory is __________.
(Methane, Urea, Acetic Acid, Glucose)
3. __________ of the following is not an organic compound.
(CH4, CO2, CH2-CH2, CH3OH)
4. __________ of the following is not an organic compound.
(Penicillin, Urea, Oxalic acid, Plaster of Paris)
5. __________ is the important sources of naturally occurring compounds of carbon.
(Animals, Plants, Rock salts, Sea water)
6. __________ is not a component of coal.
(H, O2, N, Si)
7. Hard black form of coal containing 92 – 98% carbon is called __________.
(Anthracite, Sub-bituminous coal, Bituminous coal, Lignite)
8. The most abundant form of coal and is used as energy souce and carbonization for coke, coal tar and coke-oven is called __________.
(Anthracite, sub-bituminous coal, Bituminous coal, Lignite)
9. Form of coal used at power generating stations is called __________.
(Antracite, Sub-bituminous coal, Bituminous coal, Lignite)
10. A soft and brown form of coal which contains 50 to 60% carbon is called __________.
(Anthracite, Sub-bituminous coal, Bituminous coal, Lignite)
11. In Pakistan deposits of lignite are found at __________.
(Dandot, Saindak, Khewra, none of these)
12. __________ is a pure carbon.
(Coke, Coal gas, Coal tar, none of these)
13. Its major constituents are hydrogen (50%), methane (35%) and carbon monoxide (8%).
(Coke, coal gas, coal tar, none of these)
14. Number of organic compounds present in coal tar is __________.
(115, 215, 315, 415)
15. Residue left after fractional distillation of coal tar is called __________.
(Pitch, Dutch, Gangue, Matte)
16. Petroleum in the unrefined form is called __________.
(Coke, Coal gas, Crude oil, Rock oil, both crude oil and rock oil)
17. Natural gas mainly consists of __________.
(Methane, Ethane, propane, Butanes)
18. In Pakistan there are vast reserves of natural gas at __________ in Baluchistan.
(Bandot, Khewra, Saindak, Sui)
19. __________ is a mixture of methane, ethane, propane and butane, used as a fuel and for making other organic chemicals.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
20. __________ is a mixture of hydrocarbons containing 5-8 carbon atoms and boiling in the range of 40-180°C.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
21. __________ is a mixture of hydrocarbons having 11-12 carbon atoms and boiling point in the range of 250°C.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
22. A mixture of hydrocarbons having 13-25 carbon atoms is called __________.
(Refinary gas, Gasoline, Kerosene oil, gas oil)
23. On strong heating the fractions containing the larger hydrocarbon molecules are broken up into smaller and more volatile molecules, this is called __________.
(Sublimation, Cracking, Roasting, Refining)
24. Cracking is also termed as __________.
(Pyrolysis, Refining, Polymerization, Hydrohalogenation)
25. A large number of organic compounds, especially the unsaturated ones, show a great tendency to unite. This process is termed as __________.
(Pyrolysis, Cracking, Polymerization, none of these)
26. An isomer of ethanol is __________.
(Dimethyl ether, Diethyl ether, Ethylene glycol, Methanol)
27. Organic compounds made up of carbon and hydrogen are called __________.
(Polymers, Hydrocarbons, Butanes, none of these)
28. Organic compounds other than the hydrocarbons may be considered to be derived from the hydrocarbons by the replacement of one or more of their __________ atoms with atoms or groups of atoms of other element.
(Carbon, Hydrogen, Nitrogen, none of these)
29. When ethylene is heated under pressure, a transparent solid polymer, __________ is obtained.
(Polyethene, Ethane, Methane, None of these)
30. An atom or group of atoms, which confers characteristic properties to an organic molecule, is called __________.
(Radical, Functional group, Polymer, none of these)
31. Compounds having same molecular formula but different structures are said to be __________.
(Polymers, Isomers, Radical, Functional group)
32. The quality of petroleum is determined by __________.
(Decane number, octane number, hexane number, none of these)
33. __________ of the following obey isomerism.
(CO2, C2H6O, CuSO4, none of these)
34. Two or more than two different compounds having the same molecular formula but different carbon chains or skeletons are said to be __________.
(Chain isomers, position isomers, functional group isomers, metamers)
35. The kind of isomerism which depends upon the relative position of the group, or the position of double or single bond in case of unsaturated compounds in termed as __________.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
36. Isomerism, which involves compounds having the same molecular formula, but different functional groups are called __________.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
37. __________ is exhibited by compounds having the same functional group but different alkyl attached to the same multivalent atom.
(Chain isomerism, Position isomerism, Functional Group isomerism, Metamerism)
38. In cracking usually catalyst used is __________.
(Pt, Aluminosilicate, Ni, Tetra-ethyl lead)
39. Iso-butane exhibited __________.
(Chain Isomerism, Position Isomerism, Functional group Isomerism, Metamerism)
40. In CCl4 molecule the four valencies of carbon atom are directed towards the corners of a __________.
(Cube, Hexagon, Prism, Tetrahedron)
41. Tetrahedral nature of bonding in carbon atom was first shown by __________.
(Wohler, Vant Hoff and LeBel, Lewis, Kekule)
42. The general formula (RCO)2O represents __________.
(An ether, ketone, an ester, an acid anhydride)
43. Formation of alkane by the action of zinc on alkyl halide is called __________.
(Frankland reaction, Wurtz reaction, Cannizzaro’s reaction, Kolbe’s reaction)
44. __________ of the following are isomers.
(Methyl alcohol and dimethyl ether, Ethyl alcohol and dimethyl ether, Acetone and Acetaldehyde, Proponoic acid and proponanone)
45. The isomers must have the same __________.
(Structural formula, molecular formula, chemical properties, physical properties)
46. __________ has the longest bond length.
(C = C, C º C, C – C, all of these)
47. In alkanes all C – C bonds have __________.
(single bond, double bond, triple bond, none of these)
48. Removal of one of the hydrogen atoms of an alkane produces a __________.
(alkyl group, ethyl group, methyl group, none of these)
49. Compounds in which two alkyl groups are attached to an oxygen atom are called __________.
(alkanes, ethers, alcohals, isomers0
50. Many hydrocarbons contain more than one OH groups in a molecule. Molecules of this type are called __________.
(Ethers, Polyhydroxy alcohols, aldehydes, none of these)
51. __________ is the common name of methanol.
(formaldehyde, acetaldehyde, propionaldehyde, none of these)
52. Compounds which contain carbonyl group but differ from aldehydes in that two alkyl groups are attached to the carbon of carbonyl group are called __________.
(Ethers, Ketons, Alcohols, none of these)
53. __________ is the common name of propanone.
(Acetone , ketone, Diethyl Ketone, none of these)
54. Benzene is a __________.
(Heterocyclic compound, Alicyclic compound, Aromatic compound, Acyclic)
55. Common name of formic acid is __________.
(Methanoic acid, Ethanoic acid, Propanoic acid, none of these)
56. The properties of organic compounds are due to __________.
(Covalent bonds, Functional groups, Ionic bonds, None of these)
Chapter 7
Hydrocarbons
1. Organic compounds, which contain element carbon and hydrogen only are called __________.
(Hyrocarbons, Ethers, Ketones, none of these)
2. The number of hydrocarbons is very large because of the property of hydrogen to __________, with it self in the form of chains and rings.
(Cmbine, Catenate, Sulphonation, none o these)
3. Carbon usually exhibits a covalency of __________.
(Two in most of its compounds, three in most of its compounds, four in most of its compounds, none of these)
4. Hydrocarbons, which contain single bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
5. Hydrocarbons, which contain double bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
6. Hydrocarbons, which contain triple bonds, are called __________.
(alkanes, alkenes, alkynes, none of these)
7. The alkanes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
8. The alkynes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
9. The alkenes have __________.
(tetrahedral frame work, planar molecules, linear structure, none of these)
10. Saturated Hydrocarbons are also called __________.
(Alkanes, Olefins, Alkenes, Alkanes and Olefins)
11. Unsaturated hydrocarbons are also called __________.
(Alkenes, Paraffins, alkanes, none of these)
12. Alkenes are characterized by the presence of __________ bond between two carbon atoms.
(single, double, triple, none of these)
13. Alkanes or paraffins are characterized by the presence of __________ bond between two carbon atoms.
(Single, double, triple, none of these)
14. Alkynes are characterized by the presence of __________ bond between two carbon atoms.
(single, double, triple, none of these)
15. Alkanes are also called __________.
(Paraffins, Olefins, Aldehydes, none of these)
16. Alkenes are also called __________.
(Paraffins, Olefins, Carbonyl, none of these)
17. An alkane hydrocarbon chain on cyclization would result in the formation of __________.
(Alicyclic compound, aromatic compound, ethers, none of these)
18. Benzene is the simplest example of hydrocarbon called __________.
(Alicyclic, aromatic, open chain, none of these)
19. Solid CH4 is __________.
(molecular solid, covalent solid, ionic solid, does not exist)
20. Methane is also known as __________.
(oil gas, marsh gas, gasoline, none of these)
21. A liquid hydrocarbon is converted into a mixture of gaseous hydrocarbon by __________.
(Cracking, Hydrolysis, Oxidation, Reduction)
22. __________ is obtained in the laboratory by heating a mixture of sodium acetate and soda lime.
(Alcohol, Ethene, Methane, none of these)
23. Alkenes undergo __________.
(addition reaction, substitution reaction, both addition and substitution reaction)
24. __________ does not react with aqueous solution of acids, alkalies, or potassium permanganate or other oxidizing agents and most of the usual laboratory reagents.
(Benzene, Ether, Methane, Acetic acid)
25. Bromine reacts with methane when the reaction is catalyzed by __________.
(Sunlight, high frequency radiation, diffused sunlight, nickel)
26. In methane the replacement of hydrogen by _ NO2 is called __________.
(Pyrolysis, Nitration, Halogenation, none of these)
27. Methane when heated to extreme temperature in the absence of air undergoes thermal decomposition, called __________.
(Nitration, Catalytic oxidation, Pyrolysis, none of these)
28. Urea, a useful fertilizer, is prepared on industrial scale from __________.
(Natural gas, Coal, Coke, Petroleum)
29. Carbon black is a raw material for paints and automobile tyres and is prepared from __________.
(Ethane, Ethene, Methane, none of these)
30. C2H6 is called __________.
(Methane, Ethane, Methanol, none of these)
31. __________ is obtained in the laboratory by heating sodium proponoate and soda lime.
(Methane, Ethane, Ethene, none of these)
32. In the laboratory ethane is prepared by the reaction called __________.
(Sabatier-Senderens Reaction, Pyrolysis, Catenation, Hydrohalogenation)
33. When an aqueous solution of sodium or potassium salt of mono-carboxylic acid is subjected to electrolytic, corresponding alkane is formed. This reaction is called __________.
(Sabatier-Senderens Reaction, Kolbe’s Electrolysis, Polymerization, chlorination)
34. On burning __________ produces a considerable amount of heat energy which may be used for welding process.
(Ethane, Benzene, Ethene, none of these)
35. __________ is found to be present in wood gas and coal gas.
(Methane, Ethene, Ethane, Benzene)
36. __________ is prepared on a small scale in the laboratory by heating together ethyl alcohol and sulphuric acid.
(Methane, Ethane, Ethylene, none of these)
37. The elimination of hydrogen halide (HX) from adjacent carbon atoms is called __________.
(Pyrolysis, Chlorination, Dehydrohalogenation, none of these)
38. __________ process is important in the hardening of vegetable and animals oils to produce solid fats which are used to make margarine.
(Pyrolysis, Catenation, Hydrogenation, Dehydrohalogenation)
39. When a mixture of ethene and air is passed over heated silver under pressure, we get __________.
(Epoxide, Superoxide, Suboxide, none of these)
40. The negative part of the addendum adds on to the carbon atom joined to the least number of hydrogen atoms. The statement is called __________.
(Markownikoff’s rule, Peroxide effect, Theile’s theory, Baeyer’s strain theory)
41. Baeyer’s test is the basis for detection of a __________ bond in an organic molecule.
(single, double, triple, none of these)
42. __________ was used in first world war.
(Phosgene gas, Mustard gas, Oil gas, Coal gas)
43. When a mixture of CO, C2H4 and C2H2 is passed through ammonical cuprous chloride solution then __________.
(Acetylene and CO are absorbed, CO is absorbed, C2H4 is absorbed, Nothing happens)
44. Ethylene dichloride is also called __________.
(Mustard gas, Dutch liquid, Polyethene, none of these)
45. __________ is used to manufacture mustard gas which is poisonous gas used as war gas.
(Ethane, Methane, Ethylene, none of these)
46. __________ is most found in alkenes.
(Chain isomerism, Geometrical isomerism, Mesomerism, Position Isomerism)
47. __________ poisonous gas is present in the exhaust fumes of car.
(Methane, Acetylene, HCl, Carbon dioxide)
48. __________ is used to import colour to stile green citrus fruit form ripening.
(Ethylene, Methane, Ethane, none of these)
49. The number of xylene isomers is __________.
(2, 3, 4, 5)
50. Ethylene dichloride and ethylene chloride are isomeric compounds. The statement which is not applicable to both of them is __________.
(react with alcoholic potash, react with aqueous potash and give the same product, are dihalides, answer Beilstein’s test)
51. Structure of benzene is __________.
(Diagonal, Planner, Pyramidal, Tetrahedral)
52. __________ is used in the manufacture of plastic and synthetic rubber.
(Styrene, Mustard gas, Polythene, none of these)
53. The polythene is a polymer of __________.
(Ethylene, Aceton, Propylene, Butadiene)
54. Acetylene or ethyne was discovered accidentally in 1899 by the American chemist __________.
(Wilsson, Lane, Nelson, none of these)
55. Acetylene is present in small proportions (about 0.06% by volume) in __________.
(Natural gas, Coal gas, Gasoline, Petroleum)
56. __________ is prepared in the laboratory by dropping water on calcium carbide.
(Ethylene, Acetylene, Methane, none of these)
57. The process used for the preparation of acetylene is __________.
(Berthelot Process, Sabatier-Senderns Reaction, Kolbe’s Process, none of these)
58. Acetylene has a characteristic ethereal smell resembling that of __________.
(Rotten egg, Garlic, Benzene, none of these)
59. Acetylene burns with __________ flame.
(Greenish, Bluish, Smoky, none of these)
60. Benzene was found by __________ in 1825 in the gas produced by the destructive distillation of vegetable oils.
(Hofmann, Michael Faraday, Solvay, none of these)
61. __________ found benzene in coal-tar.
(Hofmann, Michael Faraday, Solvay, none of these)
62. When n-hexane obtained from petroleum is heated in the presence of platinum at 500°C under 10 – 20 atmosphere pressure, it cyclises to give __________.
(Ether, Benzene, Mustard Gas, none of these)
63. Phenol is reduced to __________, when its vapours are passed over red hot zinc dust.
(Ether, Benzene, Ethane, Acetylene)
64. Replacement of hydrogen atom by – SO2 OH is called __________.
(Nitration, Sulphonation, Alkylation, Hydrogenation)
65. _ SO2OH is called __________.
(Sulphonic Group, Carbonyl group, Methyl group, none of these)
66. Under the influence of anhydrous aluminium chloride as a catalyst, benzene reacts with alkyl and acyl halides giving alkylated and acylated benzens. The reaction is called __________.
(Friedel-Cracts Reactions, Berthelot’s Reaction, Sabatier-Senderens Reaction, none of these)
Chapter 8
Alkyl Halides
1. Monohalo derivatives of alkanes are called __________.
(Acyl halides, Aryl Halides, Alkyl Halides, none of these)
2. The general formula of alkyl halides is __________.
(CnH2n+1 X, CnHn+1 X, C2nH2n+1 X, none of these)
3. When an alkene is treated with halogen acids, __________ is formed.
(Alkyl halide, Acyl halide, Carbonyl chloride, all of these)
4. Formula of Thionyl Chloride is __________.
(SOCl2, ZnCl2, CH3Cl, none of these)
5. If ethane is treated with HBr then __________.
(Ethyl bromide is formed, Methyl bromide is formed, Bromine is evolved, Hydrogen is obtained)
6. When metallic sodium in ether is heated with an alkyl halide, a higher alkane is formed. It is called __________.
(Sulphonation, Wurtz’s Reaction, Friedel-Crafts Reaction, none of these)
7. If sodium lead alloy is treated with methyl chloride then __________.
(Tetra ethyl lead is formed, Tetra methyl lead is formed, Tri methyl lead is formed, Di methyl lead is formed)
8. Dehydrohalogenation of alkyl halide is carried in the presence of alcoholic __________.
(NaOH, KOH, Ca(OH)2, none of these)
9. Grignard’s reagent when reacts with ammonia then __________.
(Methane is formed, Ethane is formed, Nitrogen is evolved, Magnesium is separated)
10. Grignard’s reagent reacts with alkyl halide to form __________.
(Alkanes, Alkynes, Alkenes, Alcohols)
11. Grignard’s reagents are __________.
(Alkyl halide, Alkyl magnesium halide, Alkyl sodium halide, none of these)
12. On passing CO2 through Grignard reagent __________ is formed.
(Methanoic acid, Ethanoic acid, Propanoic acid, No reaction occurs)
13. Alkyl halides (methyl chloride or ethyl chloride) when treated with __________, react to produce the important anti-knock gasoline additives.
(Sodium, Lead, Sodium-lead Alloy, none of these)
14. On adding formaldehyde to Grignard’s reagent __________ is formed.
(Primary alcohol, Secondary alcohol, Aldehyde, Acetone)
15. Action of zinc with alkyl halide in the presence of an inert solvent forms a corresponding higher alkane. This is called __________.
(Wurtz’s Reaction, Frankland Reaction, Hoffman’s Reaction, none of these)
16. The hydrolysis of alkyl halides by heating with aqueous alkali is a __________ substitution reaction.
(Electrophilic, Nucleophilic, Electrophile and Nucleophile, none of these)
17. __________ of the following compounds does not react with bromine.
(Ethylamine, Propene, Phenol, Chloroform)
18. A reaction in which an atom or group of atoms replaces an atom or group of atoms already present in the molecule of a substance is called __________.
(Nitration, Halogenation, Substitution, Sulphonation)
19. __________ is a Neucliphile.
(OH-, CN-, NH3, all of these)
20. General formula of Grignard’s reagent is __________.
(R – Mg – X, R – Al – X, R – Na – X, R – Cl – X)
21. __________ is prepared by heating methyl iodide with fresh magnesium turnings in anhydrous ether.
(Grignard’s reagent, Mustard gas, Benzene, none of these)
22. When Grignard’s reagent is hydrolyzed with water, it is converted into __________.
(Alkynes, Alkenes, Alkanes, Acetons)
23. __________ of the following alkyl halides is used as a methylating agent.
(C2H5Cl, C2H5Br, C2H5I, CH3I)
24. Ethyl chloride reacts with alcoholic KOH to give __________.
(C2H5OH, C2H6, C2H2, C2H4)
25. Dry carbon dioxide is passed through Grignard’s Reagent in the presence of __________ as a solvent.
(Acetone, Benzene, Ether, none of these)
26. Grignard’s reagent reacts with CO2 to form __________.
(HCl, Carboxylic acid, Acetic acid, Carbonic acid)
27. Grignard’s reagent reacts with acetaldehyde to form __________.
(Primary alcohol, Secondary alcohol, Tertiary alcohol, all of these)
28. Alkyl halides reacts with Zn to form __________.
(Alkynes, Alkanes, Alkenes, none of these)
Chapter 9
Organic Compounds
1. The action of nitrous acid on ethyl amine gives __________.
(Ethane, Ammonia, Ethyl alcohol, Nitroethane)
2. Isopropyl alcohol on oxidation gives __________.
(Ether, Acetone, Ethylene, Acetaldehyde)
3. Rectified spirit contains __________ % alcohol.
(95.6, 75.0, 100.0, 85.4)
4. __________ is the end product in the process of fermentation.
(Methyl alcohol, Ethanol, CH3OH, Ethylene)
5. __________ is not the characteristic of the alcohols.
(Their boiling points rise fairly uniformly with a rise in molecular weight, Lower members have a pleasant smell but burning taste and the higher ones are odourless and tasteless, these are lighter than water, Lower members are soluble in water and organic solvents but solubility decreases with increase in molecular weight)
6. In the dehydration of ethyl alcohol to ethylene with concentrated sulphuric acid __________.
(Carbonium ions are involved, carbonium are evolved, sulphuric acid acts as an electrophile, none of these)
7. A compound is an/a __________ if the “R-” group is derived from aliphatic or alicyclic hydrocarbons.
(Ether, Ketone, Alcohol, Phenol)
8. A compound which has –OH group attached to an aromatic hydrocarbon is called __________.
(Alcohol, Phenol, Ether, none of these)
9. A product formed by the reaction of sodium with ethanol is __________.
(H2O, NaOH, NaH, H2)
10. An alcohol, which contains on –OH group is called __________.
(Monohydric, Dihydric, Trihydric, none of these)
11. An alcohol, which contains on –OH group is called __________.
(Monohydric, Dihydric, Trihydric, none of these)
12. Primary, secondary and tertiary alcohols may be distinguished by using __________.
(Fehling’s solution, Victor Meyer test, Hofmann set, Beilstein test)
13. The number of structural isomers for C4H9OH is __________.
(3, 4, 5, 6)
14. In cold countries glycerol is added to water in car radiators as it helps to __________.
(bring down the specific heat of water, lower the freezing point, reduce the viscosity, make water a better lubricant)
15. Aldehydes and Ketons are commonly referred to as __________.
(Ethers, Carbonyl compounds, phenols, none of these)
16. Aldehyde may be distinguished from ketons by the use of __________.
(Concentrated Sulphyric acid, Grignard’s Reagent, Pyrogallol, Fehlings solution)
17. In aldehydes one bond of carbonyl group is always attached to __________.
(Carbon atom, Hydrogen atom, Nitrogen atom, none of these)
18. An aldehyde on oxidation gives __________.
(an alcohol, a ketone, an acid, an amine)
19. Acid anhydrides are calls of carboxylic acid derivatives, which may be formed by the elimation of __________.
(Carbon, Hydrogen, Water, none of these)
20. Formaline is an aqueous solution of __________.
(Formic acid, Formaldehyde, Flurescein, Furfuraldehyde)
21. Methyl alcohol is known commercially as __________.
(Wood-spirit, Wood Naphtha, Mustard gas, both Wood spirit and Wood- Naphtha)
22. __________ discovered Methyl alcohol.
(Boyle, Salvay, Jabber Bin Hayyan, none of these)
23. When wood is heated with an insufficient supply of air, organic materials are driven off as gases, and the cellulose is decomposed to almost pure carbon is called __________.
(Coal, Charcoal, Oil gas, Natural gas)
24. Now a days a large quantity of methyl alcohol is obtained by passing __________ over heated zinc and chromium oxides at 400 - 450°C under 200 atmospheric pressure.
(Natural gas, Water gas, Ethylene, none of these)
25. Methyl alcohol can cause __________.
(Cancer, Blindness, Aneimia, none of these)
26. The reaction of alcohol with thionyl chloride (SOCl2) in the presence of solvent called __________.
(Pyridine yields, Adenine yields, Guanine yields, none of these)
27. Ethyl alcohol often called __________.
(Alcohol, Spirit, Ether, Lacquer)
28. Ethyl alcohol is also called __________.
(Methyalted spirit, Spirit of wine, Wood spirit, none of these)
29. __________ is also present in the urine of diabetic patients.
(Spirit of wine, Wood spirit, Methane, none of these)
30. In 1808, __________ discovered ethyl alcohol in urine of diabetic patients.
(Boyl, Suassure, Mendleeve, none of these)
31. Ethyl alcohol is produced on commercial scale by the biological break down of __________,
(Starch, Minerals, Cellulase, None of these)
32. The 14 enzymes present in the living cells of the yeast are collectively called __________.
(Substrate, Zymase, Amylase, none of these)
33. The force of attraction of the electrons of one atom for the protons of another atom in close proximity is called __________.
(Ionic bond, Hydrogen bond, Covalent bond, all of these)
34. __________ of the following compounds can form a hydrogen bond.
(CH4, H2O, NaCl, CHCl3)
35. When two ice cubes are pressed over each other, they unite to form one cube. __________ of the following forces is responsible to hold them together.
(Hydrogen bond formation, Vander Waal’s forces, Covalent bond, Dopole Interaction)
36. CH3OH and C2H5OH are highly miscible with water because they exhbits __________.
(Ionic bonding, Covalent bonding, Hydrogen bonding, none of these)
37. Alcohols may be converted to the corresponding __________ by actions of halogen acids in the presence of ZnCl2.
(Aldehydes, Alkyl halides, acyl halides, none of these)
38. Compounds obtained by the elimination of a molecule of water between an alcohol and hydroxyl group of the acid are called __________.
(Ethers, Esters, Ketons, Phenols)
39. During the dehydration of alcohols, relatively high temperature and moderate alcohol concentration yield the corresponding __________.
(Ether, Olefin, Paraffin, none of these)
40. Ethyl alcohol may be identified by the __________.
(Bayer’s Test, Flame Test, Idoform Test, Chloroform Test)
41. Industrially, formaldehyde is made from methyl alcohol by __________.
(Dehydrogenation, Dehydrohalogenation, Oxidation, Reduction)
42. Dry distillation of calcium formate yields __________.
(Ether, formaldehyde, Acetic acid, none of these)
43. An aldehyde is converted to carboxylic acid on __________ with K2Cr2O7 and H2SO4.
(Reduction, Oxidation, Dehydrogenation, all of these)
44. When aldehydes are warmed with __________, red precipitates of cuprous oxide are precipitated.
(Grignard’s Reagent, Fehlings solution, KMnO4, none of these)
45. Aldehydes can be distinguished from Ketons by using __________.
(Schiff’s reagent, Concentrated sulphruric acid, Anhydrous Zinc chloride, Resorcinol)
46. In ketons the two bonds of the carbonyl are attached to two __________.
(alkyl group, aryl group, hydrogen group, alkyl group and aryl group)
47. Formation of acetaldehyde from ethanol is called __________.
(Addition, Reduction, Oxidation, Substitution)
48. Aldehydes can be distinguished from ketons by __________.
(AgNO3, CH3COOH, conc. H2SO4, Fehlings solution)
49. Acetaldehyde reacts with __________.
(nucleophiles only, electrophiles only, free radicals only, both with nucleophiles and electrophiles)
50. When aldehydes are warmed with a ammonical solution of silver nitrate, they precipitated metallic silver which often form a mirror. This reaction is called __________.
(Tollen’s Test, Fehlings Test, Idoform Test, none of these)
51. Acetaldehyde reacts with ammonia to form __________.
(Condensation products, substitution products, addition product, resin like product)
52. __________ prepared the first synthetic plastic, by combing formaldehyde with phenol under heat and pressure.
(Newlands, Blackeland, Russel, Charles)
53. __________ is used medically as a urinary antiseptic.
(Formaldehyde, Benzene, Sulphuric acid, Methanamine)
54. Aldol condensation can occur between __________.
(an aldehyde and ketone, an aldehyde and ester, an aldehyde and benzene, none of these)
55. Aldol condensation between __________ of the following compounds, followed by dehydration gives methyl vinyl ketone.
(HCHO and CH3COCH3, HCHO and CH3CHO, Two molecules of CH3CHO, Two molecules of CH3COCH3)
56. Aldol condensation can occur between __________.
(two aldehydes (identical or different), an aldehyde and ester, an aldehyde and benzene, none of these)
57. Aldol condensation can occur between __________.
(two aldehydes and phenols, two ketons(identical or different), an aldehyde and benzene, none of these)
58. A nucleophilic addition of carbonion, generated by the loss of proton from a-position of an aldehyde or a ketone by a base, to the carbonyl group, is called __________.
(Nitration, Aldol Condensation, Esterification, none of these)
59. The aldehydes having no hydrogen attached to a-carbon atom when treated with concentrated solution of an alkali, undergo self-oxidation and reduction, forming a mixture of an alcohol and a salt of corresponding carboxylic acid. The reaction is known as __________.
(Fehlings reaction, Cannizzaro reaction, Formalin reaction, none of these)
60. An aqueous solution containing about 40% of formaldehyde and a little alcohol is sold under the name of __________.
(Formalin, Malt-sugar, Pyridine, Starch)
61. Gelatine, a substance readily soluble in water, becomes insoluble when it is treated with __________.
(Formalin, Malt sugar, Benzene, Resins)
62. __________ is used as preservative for biological specimens.
(Benzene, Ketone, Alcohol, Formaline)
63. Alive polio virus in the culture fluid is made harmless by addition of __________ in the processing of anti-virus vaccine.
(Benzene, Acetic acid, formaldehyde, Carboxylic acid)
64. Acetic acid is manufactured from the brown aqueous distillate known as __________ which is obtained by the destructive distillation of wood and contains a mixture of acetic acid, acetone and methyl alcohol.
(Formalin, Pyroligenous acid, Pyridine, Acetylene)
65. The most general method of preparing __________ is by oxidation of corresponding aldehydes or primary alcohols.
(Phenols, Carboxylic acids, ketones, none of these)
66. The chemical properties of the carboxylic acids depend chiefly on the __________.
(Hydroxyl group, Carbonyl group, Methyl group, none of these)
67. __________ is used for coagulating rubber and latex and curing fish as well.
(Alcohol, Acetic acid, Wood spirit, none of these)
68. Ethyl acetate is an example of a important class of substance known as __________.
(Ketones, Esters, Alcohols, none of these)
69. Ethyl acetate (an ester) can be prepared by the action of __________ on carboxylic acid, in the presence of acidic media.
(Phenols, Formalin, Pyradine, Alcohol)
70. Molecular hydrogen in presence of suitable catalysts reduces carbonyl compounds to __________.
(aCetones, Ethers, Esters, Alcohols)
71. __________ is used as a nail-polish remover.
(acetone, Benzene, Idoform, none of these)
72. Acetone may be converted into propane by heating with __________.
(conc HCl and 24/Hg, Mg + H2O, conc HI and red P, Zn/Cu couple and ethanol)
73. __________ is the solvent used in the preparation of Grignard’s reagent and in Wurtz reaction.
(Ethers, Phenoles, Ketons, Alcohols)
74. The hydroxyl group derivatives of aromatic hydrocarbons, which have the –OH group directly bonded to the ring carbon atoms are called __________.
(Esters, Acetons, Alcohols, Phenols)
75. Carbolic acid is prepard from __________.
(Dow’s Process, Down’s Process, Nelson’s Process, none of these)
76. Phenol is colourless, poisonous __________.
(Liquid, Gas, Solid, none of these)
77. Above __________ °C phenol is miscible with water in all proportions, but below this temperature, it is only partially miscible.
(78.5, 68.5, 58.5, none of these)
78. Phenol is reduced to __________ when its vapours are passed over red hot zinc dust or distilled in the presence of zinc dust.
(Alcohol, Benzene, acetone, none of these)
79. Action of zinc with alkyl halide in the presence of an inert solvent forms a corresponding higher alkane. This is called __________.
(Wurtz’s reaction, Frankland’s reaction, Hoffman’s reaction, none of these)
80. The hydrolysis of alkyl halides by heating with aqueous alkali is a __________ substitution reaction.
(Electricphilic, Nucleophilic, Electrophilic and Nucleophilic, none of these)
81. __________ is prepared by heating methyl iodide with fresh magnesium turnings in anhydrous ether.
(Grignard’s reagent, Mustards gas, Benzene, none of these)
82. Dry carbon dioxide is passed through Grignard’s reagent in the presence of __________.
(Acetone as a solvent, Benzene as a solvent, Ether as a solvent, none of these)
Chapter 10
Chemistry of Life
1. Starch is a polymer of __________.
(Glucose, Fructose, Lactose, Maltose)
2. A material cannot be termed as food unless it contains at least one __________.
(Vitamine, Mineral, Nutrient, Amino acid)
3. On heating glucose with Fehling’s solution we get a precipitate of colour __________.
(Yellow, Red, Black, Green)
4. It is the best to carry out reactions with sugars in neutral or acid medium and not in alkaline medium. This is because in alkaline medium sugars undergo __________ of the following changes.
(Racemisation, Decomposition, Inversion, Rearrangement)
5. __________ food component regulates body processes.
(Minerals, Fats, Proteins, Carbohydrates)
6. The process by which large non-diffusuble organic molecules are converted into smaller diffusible molecules is known as __________.
(Ingestion, Fermentation, Decomposition, Digestion)
7. The solution of sugar in water contains __________.
(Free atoms, Free ions, Free molecules, Free atoms, and free molecules)
8. During digestion carbohydrates are broken down to __________.
(Glucose, Amino acids, Fatty acids, None of these)
9. During digestion proteins are broken down to __________.
(Glucose, Amino acids, Fatty acids, none of these)
10. __________ of the following gives a deep blue colour with a drop of dilute solution of iodine.
(Cellulose, Glucose, Starch, Sugar)
11. During digestion fats are broken down to __________.
(Glucose, Amino acids, Fatty acids, none of these)
12. The use of the products of digestion in synthesis of cellular structure is known as __________.
(Metabolism, Assimilation, Homeostasis, None of the above)
13. The percentage of glucose in human blood is __________.
(0.1, 0.2, 9.3, 0.4)
14. Carbohydrates supply about __________ of energy per gram.
(4 kcal, 2 kcal, 2 kcal, 1 kcal)
15. The main source of cellulose is __________.
(cotton, wood, both cotton and wood, none of these)
16. Fats provide about __________ of energy per gram.
(4kcal, 2 kcal, 9kcal, 5kcal)
17. Of the following, __________ is a high-energy food.
(Proteins, Fats, Carbohydrates, none of these)
18. Glucose and fructose are __________.
(Geometrical Isomers, Metamers, Optical Isomers, none of these)
19. __________ isomers of glucose are known.
(4, 8, 16, 32)
20. The digestion of carbohydrates begins with the mastication in the mouth, where enzyme __________ of the saliva hydrolyses some of the starch to maltose.
(Ptyalin, Amylase)
21. Human body tissue contains __________% carbohydrates.
(1, 2, 3, 4)
22. Carbohydrates are ultimately converted into glucose and other simpler products in the __________.
(Mouth, Stomach, Small intestine, Large intestine)
23. The use of products of digestion in synthesis of cellular structures is called __________.
(Assimilation, Metabolism, Excretion, Digestion)
24. The products of oxidation of glucose are __________.
(Carbon dioxide and water, Oxygen and Hydrogen, Carbon dioxide and hydrogen, none of these)
25. Glucose is termed as __________.
(Single nutrient food, double nutrient food, multi nutrient food, none of these)
26. Deficiency of all nutrients leads to __________.
(Nutrition, Malnutrition, Under Nutrition, none of these)
27. The recommended daily intake of protein per kilogram of the body weight is __________.
(0.8 gm, 0.9 gm, 0.6 gm, 1.0 gm)
28. Lipids and Proteins are made of __________.
(Macromolecule, Micromolecule, Microatom, None of these)
29. The digestion of proteins begins in the __________.
(Mouth, Stomach, Small intestine, Large intestine)
30. The enzyme __________ of gastric juice, catalyses the hydrolysis of peptide linkage in protein molecules.
(Renin, Trypsin, Pepsin, Amylase)
31. In the mouth of some of the starch is hydrolyzed to maltose by the action of enzyme __________.
(Ptylin, Lipase, Renin, Amylase)
32. In the body dietary proteins are the source of __________,
(Amino acids, Fatty acids, Lipids, none of these)
33. A large class of compounds that are polyhydroxy aldehydes or ketones, or substances that yield such compounds upon acid hydrolysis are called __________.
(Fats, Carbohydrates, Proteins, vitamins)
34. Plants are able to synthesis their own carbohydrates from CO2 of the air and water taken from the soil in the presence of sunlight and chlorophyll. This process is called __________.
(Nutrition, Assimilation, Photosynthesis, Homeostasis)
35. Human diet consist of 60 – 65% by mass of the average diet on __________.
(Fats, Carbohydrates, Proteins, vitamins)
36. Carbohydrates, which have three to nine carbon atoms and are not hydrolysable are called __________.
(Monosacchrides, Ddi-saccharides, Poly-saccharides, None of these)
37. The carbohydrates, which have three to nine carbon atoms and are not hydrolysable are called __________.
((Monosacchrides, Ddi-saccharides, Poly-saccharides, None of these)
38. The balanced diet contains amount __________ per day.
(60 gm, 70 gm, 80 gm, 90 gm)
39. Glucose is __________.
(a monosacchride carbohydrate, a di-saccharide carbohydrate, a poly-saccharide carbohydrate, none of these)
40. A class of carbohydrates which are formed by the condensation of two or more monosaccharide units with the loss of water molecules are called __________.
(Disaccharides, Poly saccharides, Pentoses, none of these)
41. Sucrose is an example of __________.
(a monosacchride carbohydrate, a di-saccharide carbohydrate, a poly-saccharide carbohydrate, none of these)
42. On hydrolysis __________ is broken down into two simpler sugars glucose and fructose.
(Glucose, Sucrose, Maltose, none of these)
43. Glucose is also called __________.
(Dextrose, Maltose, Fructose, Mannose)
44. Corn syrup contains __________.
(Glucose, Fructose, Mannose, Maltose)
45. Fructose occurs in many __________.
(Cereals, Fruits, Vegetables, none of these)
46. Honey is a mixture of __________.
(Glucose and Fructose, Glucose and Maltose, Fructose and Mannose, Glucose and Fructose with vitamins and minerals)
47. The carbohydrates, which contain hundreds to thousands of monosacchride units are called __________.
(Polysacchrides, Oligosaccharides, Hexoses, None of these)
48. Cellulose is an example of __________.
(Monosaccharides, Di-saccharides, Polysaccharides, None of these)
49. The main difference between starch and cellulose is the type of links between __________.
(Mannose units, Glucose units, Fructose, units, none of these)
50. Vitamin was discovered by __________.
(Casimir Funk, Blackeland, Hopkins, Elmer)
51. Vitamin A was discovered by __________.
(Elmer McCollum, Casimir funk, Hopkins, none of these)
52. Vitamin D was discovered by __________.
((Elmer McCollum, Casimir funk, Hopkins, none of these)
53. Fat-soluble vitamins are found associated with __________ in natural foods.
(Renin, Lipids, Peptides, Maltose)
54. Fat soluble vitamins include __________.
(Vitamin A, B, C, D, Vitamin A, B, C, Vitamin A, D, E, K, Vitamin K)
55. Water-soluble vitamins include __________.
(Vitamin A, B, Vitamin A, B, C, vitamin B, C, Vitamin A, C)
56. Vitamin B1 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
57. Vitamin B2 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
58. Vitamin B5 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
59. Vitamin B6 is called __________.
(Thiamin, Riboflavin, Niacin, Pyridoxine)
60. Vitamin B12 is called __________.
(Cyanocoalamine, Riboflavin, Niacin, Pyridoxine)
61. Most water-soluble vitamins act as __________.
(Enzymes, Coenzymes, Coenzymes or are required for the synthesis of coenzymes, none of these))
62. People who consume too much vitamin __________, may develop bone pain, bone like deposits in the kidneys, and mental retardation.
(A, B, C, D)
63. Edible lipids constitute approximately __________ % of the diet of an average person.
(25-28, 25-30, 25-32, 25-35)
64. The most important energy storage compounds in the animal kingdom are __________.
(Peptides, Lipids, Amino acids, none of these)
65. Plants store most of the energy in the form of carbohydrates primarily as __________.
(Amino acids, Starch, Cellulose, Maltose)
66. The nutrients of our food which provide insulation for the vital organs, protecting them from electrical shocks and maintaining optimum body temperature are called __________.
(Amino acids, Steroids, Lipids, Fatty acids)
67. Lipids that contain both polar and non polar groups are integral components of __________.
(Cell wall, Cell membrane, Cytoplasm, Mitochondria)
68. Steroids is an important type of __________.
(Proteins, Vitamins, Lipids, Carbohydrates)
69. The most abundant and the most important steroid in the human body is __________.
(Riboflavin, Cholestrol, Folic acid, Inositol)
70. __________ is an important precursor in the biosynthesis of sex-hormones, synthesis of adrenal hormones and vitamin D.
(Insitol, Cholestrol, Lipoic Acid, Biotin)
71. On the average, more than 50% of the total dry weight of the cells is composed of __________.
(Carbohydrates, Proteins, Fats, Water)
72. The Dutch chemist, GJ Mulder (1883), is credited as being one of the first scientists to recognize the importance of __________.
(Vitamins, Carbohyrates, Proteins, Fats)
73. __________ organic compound is a major structural component of an animal tissue.
(Carbohydrates, Proteins, Cellulose, Lipids)
74. Hormones are made of __________.
(Proteins, Fats, Carbohydrates, Lipids)
75. Antibodies are __________.
(fats in nature, carbohydrates in nature, protein in nature, vitamins in nature)
76. Enzymes are __________.
(carbohydrates in nature, proteins in nature, fats in nature, none of these)
77. Haemoglobin is a __________.
(Protein, Carbohydrate, Fat, Mineral)
78. The primary function of proteins is __________.
(Energy supply, body building, body building and maintenance, protection of body)
79. __________ nutrients of food are stored by the body as energy reserves.
(Carbohydrates and lipids, proteins and lipids, proteins and carbohydrates, none of these)
80. for a normal adult with a constant weight, the recommended daily intake of protein is approximately __________ gram per kg of body weight.
(0.2, 0.4, 0.6, 0.8)
81. 33% - 43% protein is present in __________.
(Food yeast, Soya bean, Rice, Cheese)
82. The percentage of protein in chicken food is __________%.
(28, 21, 33, 12)
83. The protein in milk is __________%.
(2, 3, 12, 19)
84. Fats are esters of glycerol and __________.
(Faty acids, Lipids, Steroids, none of these)
85. The percentage of protein in egg is __________%.
(12-18 , 12-24, 12-36, 12-48)
86. The percentage of protein in flour is __________%.
(18, 12, 6, 3)
87. The percentage of protein in fish is __________%.
(18-21, 12-18, 6-36, 3-9)
88. The percentage of protein in rice is __________%.
(6-7, 2-3, 5-11, 11-19)
89. The percentage of protein in fresh vegetables is __________%.
(5-6, 7-17, 4-7, Rarely contains 2-3)
90. Amino acids are the building blocks of __________.
(Carbohydrates, Proteins, Lipids, Fats)
91. Proline amino acids have __________ group and –COOH group attached to the same carbon atom.
(-NH3, -NH2, -NH, -OH)
92. Amino acids are widely classified __________.
(according to the number of –NH2 group, according to the number of –COOH group, according to polarity of their side chain, all of these)
93. The first amino acid was isolated in 1806 and was given the name __________.
(Asparangine, Glycine, Renin, Maltose)
94. The major amino acid found in gelatin is __________.
(Glycine, Asparangine, Renin, none of these)
95. Esters of Glycerol and Fatty acids are called __________.
(Acids, F, Proteins, Carbohydrates)
96. Among the most important of the natural __________ are the cotton seed oil, corn oil, butter, tallow and olive oil.
(Fats, Proteins, Carbohydrates, Vitamins)
97. Unsaturated vegetable oils, such as cotton seed oil are converted into fast on __________.
(Oxidation, Dehydration, Hydrogenation, Sulphonation)
98. The hydrogenation of oils is accomplished easily by bubbling hydrogen into the oil in the presence of catalyst __________.
(Pt, Ni, Zn, ZnO)
99. Naturally occurring fatty acid nearly always have an/a __________ number of carbon atoms.
(Even, Odd, Even and odd, none of these)
100. Liquid fats are called __________.
(Fatty acids, Oils, Ketones, Lipids)
101. The degree of undaturation of a fat or oil is usually measured by the __________.
(number of carbon atoms, number of hydrogen atoms, iodine number, none of these)
102. The number of grams of iodine that will be consumed by 100 grams of fat or oil is called __________.
(Iodine complex, Iodine number, Iodoform, None of these)
103. Brain cells are made of __________.
(Proteins, Fats, Carbohydrates, Lipids)
104. Nerve tissues are made of __________.
(Fats, Proteins, Carbohydrates, Steroids)
105. Fat-soluble vitamins are obtained from __________.
(Carbohydrates, proteins, fats, lipids)
106. Vegetable oils such as peanut oil contain vitamin __________.
(A, B, C, E)
107. Milk fat, butter, cream, and fish liver oil contain vitamin __________.
(A, B, C, A and D)
108. Our balanced diet contains 70 grams per day of __________.
(Carbohydrates, Proteins, Fats, None of these)
109. About 35% of our daily caloric requirements are obtained from __________,
(Carbohydrates, Proteins, Fats, Vitamins)
110. __________ is the term used to reflect the development of any disagreeable odour in the fat or oil.
(Acidity, Basicity, Rancidity, none of these)
111. Two principal chemical reactions responsible for causing rancidity are __________.
(Oxidation and Hydrogenation, Oxidation and Hydrolysis, Hydrolysis and fermentation, Oxidation and Pyrolysis)
112. The reaction of fat with a strong base such as NaOH to produce glycerol and the salt of a fatty acid is used to produce __________.
(Soap, Glucose, Vegetable oil, Gastric Juice)
113. The word enzyme has a __________.
(Greek origin, Latin origin, Roman origin, Arabic origin)
114. In living systems enzymes catalyze reactions at __________°C.
(0, 25, 100, 37)
115. The substance upon which an enzyme acts is known as its __________.
(base, substrate, nutrient, pair)
116. The amount of enzyme, which will catalyze the transformation of one micro-mole of a substrate per minute is termed as __________.
(Substrate, potency, activity, specific activity)
117. Units of enzyme per milligram of proteins are termed as __________.
(activity, potency, turn over, none of these)
118. The number of moles of substrate transformed per mole of enzyme per minute at a definite temperature is called __________.
(Potency, Turn over, Activity, none of these)
119. Enzymes are most commonly named by adding the suffix to the root of the name of the substrate __________.
(ose, ase, ane, ene)
120. Urease acts upon __________.
(Sucrose, Urea, Ammonia, Starch)
121. Sucrose is also called __________.
(invertase, Urea, Renin, Amylase)
122. __________ is an enzyme.
(Sucrose, Sucrase, Maltose, Urea)
123. __________ enzyme was first obtained by grinding pancreatic tissue with glycerol.
(Amylase, Urea, Ascorbic Acid Oxidase, Trypsin)
124. The site of the enzyme, which combines with the substrate, and at which transformation from substrate to products occurs, is called he __________.
(Cellular site, Active site, Vacant site, Complex)
125. The main factors, which effect enzyme activity, are __________.
(concentration, temperture and pH, concentration, temperature, pH and co-enzymes, concentration, temperature, pH, co-enzymes (activators and inhibitors) and radiation, co-enzymes, activators and inhibitors)
126. The majority of enzymes are most active at about __________ °C.
(35, 45, 55, all of these)
127. Many enzymes contain a protein part and a non-protein part. The protein part is called the __________.
(Apoenzyme, Coenzyme, Enzyme, none of these)
128. The non-protein part in enzyme is termed as __________.
(Apoenzyme, coenzyme, substrate, all of these)
129. Examples of co-enzymes are __________.
(Vitamins, Compounds derived from vitamins, Vitamins or compounds derived from vitamins, all of these)
130. In organic substances that tend to increase the activity of an enzyme are called __________.
(activators, Inhibitors, Apoenzymes, coenzymes)
131. Magnesium ion is an inorganic activator for the enzyme __________.
(Trypsin, Carbonic anhydrate, Sucrase, Phosphatase)
132. Zinc ion is an activator for the enzyme __________.
friendsmania.net
(Amulase, Carbonic anhydrase, Renin, Phosphatase)
133. Substances, which tend to decrease the activity of enzyme are called __________.
(Activators, Accelerators, Inhibitors, Retarders)
134. Enzymes are generally inactivated rapidly by exposure to __________.
(Ultraviolet light, b-rays, g-rays, X-rays, all of these)
Chapter 11
Chemical Industries in Pakistan
1. The substances added to the soil to provide one or more nutrient elements essential for plants growth are called __________.
(Growth hormones, Minerals, Fertilizers, Salts)
2. The substances added to the soil in very small amounts (about 6 grams to 200 grams per acre) are called __________.
(Macronutrients, Micronutrients, Fertilizers, none of these)
3. Fertilizers are classified into __________.
(two major categories, three major categories, four major categories, none of these)
4. Natural fertilizers are materials derived from __________.
(plants, animals, algae, all of these)
5. A natural fertilizer provide about __________ kg of nitrogen.
(4.5, 3.2, 2.2, 1.5)
6. A natural fertilizer provides __________ kg of P2O5.
(4.5, 3.2, 2.2, 1.5) A
7. A natural fertilizer provides __________ kg of potash (K2O).
(4.5, 3.2, 2.2, 1.5)
8. The percentage of nitrogen in ammonia is __________%.
(32, 55, 82, 25)
9. The percentage of nitrogen in ammonium Nitrate is __________%.
(32-33.5, 50-55, 80-82, 20-25)
10. The percentage of nitrogen in ammonium sulphate is __________%.
(27, 21, 23, 19)
11. The percentage of sulphur in ammonium sulphate is __________%.
(25, 21, 23, 19)
12. The percentage of nitrogen in Urea is __________%.
(37, 50, 46, 82)
13. Ammonia when used directly as a fertilizer is to be injected about __________ under the surface to keep it from seeping out.
(2 inches, 4 inches, 6 inches, 8 inches)
14. Ammonium nitrate is sold as a mixture with __________.
(Soda Ash, Limestone, Zinc, None of these)
15. The percentage of nitrogen in Diammonium hydrogen phosphate is __________%.
(16, 48, 32, 64)
16. The percentage of P2O5 in diammonium hydrogen phosphate is __________%.
(16, 32, 48, 64)
17. A fertilizer; potassium chloride is sold as __________.
(Muriate of potash, Mixture of potash, Potency of potash, none of these)
18. The percentage of K2O in potassium chloride is __________%.
(60-63, 50-70, 40-80, 30-90)
19. Potassium sulphate with 48% to 52% potash, is made from __________.
(Potassium Phosphate, Potassium Chloride, Potassium Nitrate, none of these)
20. __________ is preferred for horticultural crops and for tobacco and potatoes.
(Potassium chloride, Potassium sulphate, Potassium Nitrate None of these)
21. __________ is used for fruits, vegetables and tobacco.
(Potassium chloride, Potassium sulphate, Potassium Nitrate None of these)
22. Any material, which changes the cleaning effect of water, is called __________.
(Fertilizers, Detergent, Acid none of these)
23. __________ are sodium and potassium salt of long chain fatty acids.
(Soaps, Detergents, Fertilizers, None of these)
24. __________ contain sodium or potassium salts of aryl or alkly sulphonated acids as one of their constituents.
(Soaps, Detergents, Fertilizers, none of these)
25. Soap is a surfactant of the type __________.
(anionic, cationic, nonionic, none of these)
26. __________ is best in its cleaning action.
(Soap, Detergents, Surfactant, None of these)
27. Hydrolytic reaction of fat with caustic soda is known as __________.
(Esterification, Saponification, Acetylation, Carboxylation)
28. Turpentine is obtained from __________.
(Oak tree, Pine tree, Birch tree, Lemon tree)
29. __________ surfactants perform well over a wide range of water hardness and pH.
(Anionic, Cationic, Nonionic, none of these)
30. Fats and oils are __________.
(Acids, alcohols, salts, none of these)
31. Washing soap can be prepared by saponification with alkali of __________ of the following oil.
(Rose oil, Paraffin oil, Groundnut oil, Kerosene oil)
32. Commercial detergents contain mainly __________.
(RCOON, RONa, RSNa, ROSO3Na)
33. Sodium tripolyphosphate is __________.
(a surfactant, a builder, a auxiliary agent, none of these)
34. In glass or vitreous state solid the atoms are arranged in __________.
(Regular fashion, Random fashion, Linear fashion, none of these)
35. Glass was first made by about __________.
(40BC, 400BC, 4000BC, none of these)
36. The number of glass products now manufactured is __________.
(25,000, 50,000, 75,000, none of these)
37. The substance that can form the glassy, non-crystalline structure is called __________.
(Formers, Fluxes or modifiers, Stabilizers, none of these)
38. The principle former of almost all glasses is __________.
((SiO2)n, (SiO3)n, (SiO2)X, none of these)
39. Chemical compounds, which are added to reduce the reactivity of glass, are called __________.
(Formers, Modifiers, Stabilizers, none of these)
40. __________ is used as stabilizer.
(Ca2O, SiO2, Na2O, none of these)
41. In glass making the whole combination of ingredients is called a __________.
(Gangue, Batch, Mixture, none of these)
42. The melting of nearly all glass is done in a continuous tank furnace, which operates steadily over periods of up to __________.
(a day, a month, a year, none of these)
43. __________ is a heat-treatment cycle that prevents glass from harmful stress.
(Forming, Annealing, Batching, none of these)
44. __________ is used for Annealing.
(Klin, Batch, Converter, Oven)
45. The main constituents of __________ are boron oxide and silica.
(Pyrex glass, Soda-lime glass, Low silica glass, Fibrous glass)
46. In Pakistan how many units are involved in the production of glass __________.
(20, 25, >25, none of these)
47. In Pakistan the total production of glass is over __________ tons per year.
(800, 8000, 80,000, none of these)
48. Asbestos is a __________.
(Mineral fibre, Animal fibre, Vegetable fibre, none of these)
49. __________ is the fibre in which the basic polymer (fibre forming substance) is a long chain composed of least 85% by weight of Acrylonitrile units.
(Acrylic Fibre, Modacrylic fibre, Polyster fibre, Rayon Fibre)
50. The fibre, which has less than 85% but more than 35% proportion by weight, of acrylonitrile units is called __________.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
51. __________ is the fibre in which the fibre-forming substance is a long chain synthetic polymer composed of at least 85% by weight of an ester of a dihydric alcohol and terephthalic acid.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
52. __________ is a fibre composed of regenerated cellulose in which substituents have replaced nor more than 15% of the hydrogen of the hydroxyl group.
(Acrylic fibre, Modacrylic fibre, Polyster fibre, Rayon fibre)
53. __________ compound contains cellulose acetate as fibre forming substance.
Chemistry True and False 2nd year 2010
1. PVC is a polymer of benzene.
2. Fructose is a reducing sugar.
3. The deficiency of vitamin C causes scurvy.
4. Methanol causes blindness.
5. Diamond is the hardest known substance in the world.
6. The properties of boronoxide are acidic.
7. Graphite is a good conductor of electricity.
8. The deficiency of vitamin A causes night-blindness.
9. Wurtz reaction can be used to prepare Methane.
10. Bakelite is polymer of phenol and alkyl halide.
11. The heat of hydration of Li+ ion is equal to that of Cs+ ion.
12. The molecule of H2S is non-linear.
13. CuSO4 in excess of NH3 forms Cu(OH)2.
14. Compounds have benzene ring are called aeromatic.
15. Polyethenes are the most common plastics.
16. Lead-containing paints are banned because of the high cost.
17. Na2CO3 decomposes on heating.
18. The atomic weights of isotopes are different because of the difference in the number of protons.
19. Gastric juice is pale yellow in colour.
20. Ascorbic acid is enzyme.
21. The main function of carbohydrates is to circulate blood.
22. The preparation of vegetable ghee is a dehydrohalogenation process.
23. There are eight periods and seven groups in the Periodic table.
24. Hydrated copper sulphate is a white crystalline solid.
25. Pure diamond is colourless.
26. The first transition series starts from scandium and ends at zinc.
27. Markownikoff’s rule is not applicable to alkynes.
28. Methylated spirit is ethanol containing some methanol.
29. A functional group is the most reactive part of the molecule.
30. Vitamins A.D.K are water-soluble vitamins.
31. Kerosene oil is a petroleum product.
1. PVC is a polymer of benzene.
2. Fructose is a reducing sugar.
3. The deficiency of vitamin C causes scurvy.
4. Methanol causes blindness.
5. Diamond is the hardest known substance in the world.
6. The properties of boronoxide are acidic.
7. Graphite is a good conductor of electricity.
8. The deficiency of vitamin A causes night-blindness.
9. Wurtz reaction can be used to prepare Methane.
10. Bakelite is polymer of phenol and alkyl halide.
11. The heat of hydration of Li+ ion is equal to that of Cs+ ion.
12. The molecule of H2S is non-linear.
13. CuSO4 in excess of NH3 forms Cu(OH)2.
14. Compounds have benzene ring are called aeromatic.
15. Polyethenes are the most common plastics.
16. Lead-containing paints are banned because of the high cost.
17. Na2CO3 decomposes on heating.
18. The atomic weights of isotopes are different because of the difference in the number of protons.
19. Gastric juice is pale yellow in colour.
20. Ascorbic acid is enzyme.
21. The main function of carbohydrates is to circulate blood.
22. The preparation of vegetable ghee is a dehydrohalogenation process.
23. There are eight periods and seven groups in the Periodic table.
24. Hydrated copper sulphate is a white crystalline solid.
25. Pure diamond is colourless.
26. The first transition series starts from scandium and ends at zinc.
27. Markownikoff’s rule is not applicable to alkynes.
28. Methylated spirit is ethanol containing some methanol.
29. A functional group is the most reactive part of the molecule.
30. Vitamins A.D.K are water-soluble vitamins.
31. Kerosene oil is a petroleum product.
Answers
to True and False
Five Year Papers
1. False
2. True
3. True
4. True
5. False
6. True
7. True
8. False
9. False
10. False
11. True
12. False
13. True
14. True
15. False
16. True
17. False
18. False
19. False
20. False
21. False
22. False
23. False
24. False
25. True
26. True
27. False
28. True
29. True
30. False
31. True
Five Year Papers
1. False
2. True
3. True
4. True
5. False
6. True
7. True
8. False
9. False
10. False
11. True
12. False
13. True
14. True
15. False
16. True
17. False
18. False
19. False
20. False
21. False
22. False
23. False
24. False
25. True
26. True
27. False
28. True
29. True
30. False
31. True
Chemistry
XII Fill in the Blanks
Five Year Papers
1. Plastics are polymers of __________.
2. From crude oil, additional quantity of petrol is obtained by __________ process.
3. Tertiary alkyl halides react by __________ reaction mechanism.
4. __________ period is incomplete.
5. Elements, which follow actinium, are called __________ elements.
6. Ionic hydrides are also called __________.
7. Compounds with the general formula CnH2n + 2O are called __________.
8. Resorcinol is not an alcohol but a __________.
9. A ketone contianing different alkyl radicals is called __________ ketone.
10. The hydrolysis of fats and oils with a strong alkali is called __________.
11. __________ is active in the stomach of young children.
12. The chemical name of Lunar caustic is __________.
13. Aluminium resists corrosion due to the formation of __________.
14. EDTA is a __________ ligand.
15. The chemical formula of rust is __________.
16. Sub-Group B elements are called __________ elements.
17. The hybridization of carbon in graphite is __________.
18. The chemical name of vitamin B2 is __________.
19. The reactions between metallic sodium and alkyl halides are called __________ reaction.
20. The fractional distillation of crude petroleum yields only __________% petrol.
21. Starch and Cellulose are the examples of __________ carbohydrates.
22. AgCl dissolves in ammonia to form __________.
Five Year Papers
1. Plastics are polymers of __________.
2. From crude oil, additional quantity of petrol is obtained by __________ process.
3. Tertiary alkyl halides react by __________ reaction mechanism.
4. __________ period is incomplete.
5. Elements, which follow actinium, are called __________ elements.
6. Ionic hydrides are also called __________.
7. Compounds with the general formula CnH2n + 2O are called __________.
8. Resorcinol is not an alcohol but a __________.
9. A ketone contianing different alkyl radicals is called __________ ketone.
10. The hydrolysis of fats and oils with a strong alkali is called __________.
11. __________ is active in the stomach of young children.
12. The chemical name of Lunar caustic is __________.
13. Aluminium resists corrosion due to the formation of __________.
14. EDTA is a __________ ligand.
15. The chemical formula of rust is __________.
16. Sub-Group B elements are called __________ elements.
17. The hybridization of carbon in graphite is __________.
18. The chemical name of vitamin B2 is __________.
19. The reactions between metallic sodium and alkyl halides are called __________ reaction.
20. The fractional distillation of crude petroleum yields only __________% petrol.
21. Starch and Cellulose are the examples of __________ carbohydrates.
22. AgCl dissolves in ammonia to form __________.
Chapter
1
Periodic Classification of Elements
1. In 1913 Moseley, A British physicist, found that a __________ is the fundamental property of an atom.
2. In the modern Periodic table recommended by the International Union of Pure and Applied Chemistry (IUPAC) in 1982, the elements are arranged in the ascending order of __________.
3. Horizontal rows of elements in the periodic table are called __________.
4. The vertical columns of elements arranged in the Periodic table are called __________.
5. In the Modern Periodic Table there are __________ periods.
6. The first period of Modern Periodic Table contains __________elements.
7. Hydrogen lies in __________ Period.
8. Helium lies in __________ Period.
9. All the elements belonging to the second period are __________.
10. Second period contains __________ elements.
11. The elements of the second period of the modern Periodic table are __________.
12. Third period of periodic table contains __________ elements.
13. The elements of the fourth period of the modern periodic table are __________.
14. Fourth period of Modern Periodic Table contains __________ elements.
15. Fifth period of Modern Periodic Table contains __________ elements.
16. Those elements, which have ‘d’ orbitals in the process of completion in the form of ions or atoms, are called __________.
17. Elements in IB group are called __________.
18. Those elements, which involve ‘s’ orbital filling in their valence shells, are called __________.
19. The sixth period of Modern Periodic Table contains __________ elements.
20. The longest period of modern Periodic Table is __________.
21. The eight ‘s’ and ‘p’ block elements in the 4th and 5th periods are known as __________.
22. The elements of group IA and IIA are classified as __________ elements.
23. The seventh period of modern Periodic table contains __________ elements.
24. The elements on the right hand side of the Periodic table are called __________.
25. The outer most shell involved in chemical bonding are called __________.
26. The number of electrons in the outermost or valence shells is called __________.
27. Na2O is strongly __________ in nature.
28. Cl2O7 is strongly __________ in nature.
29. Greater the electronegativity of an element, stronger is the __________ character of its oxide.
30. In case of transition elements, the last electrons are received by __________.
31. Elements in group IB, IIB through VIIB are known as __________.
32. Elements in group IB, IIB through VIIB are known as __________.
33. Elements in the group VI A and __________ are the most active non-metals.
34. The correct order of second ionization potential of carbon, nitrogen, oxygen and fluorine is __________.
35. The elements having seven valence electrons are known as __________.
36. The elements of group IIIA to VIIA are called __________.
37. Maximum number of electrons present in sixth period is __________.
38. The elements of group VIIIA are called __________.
39. In case of inner transition elements the last electrons are received by __________.
40. In case of outer transition elements the last electron are received by __________.
Chapter 2
Hydrogen
1. Hydrogen was first prepared by Cavendish in 1766 by the action of __________.
2. Hydrogen is evolved by the action of cold diluted HNO3 on __________.
3. Hydrogen is found in nature in combined state. The most abundant compound of hydrogen is __________.
4. The electronic configuration of hydrogen atom is __________.
5. Hydrogen forms slat like hydrides with the elements of __________.
6. Hydrogen forms interstitial hydrides with the elements of __________.
7. An example of covalent hydride is __________.
8. Alkali metals need __________ electron to complete their outermost shells.
9. The number of isotopes of hydrogen is __________.
10. 1H1 is symbol of __________.
11. 1H2 is the symbol of __________.
12. 1H3 is the symbol of __________.
13. The number of neutrons in the nuclei of tritium atom is __________.
14. The number of neutrons in the nucleus of protium is __________.
15. The mass number of deutrium is __________.
16. Tritium is present to the extent of one atom in __________ atoms.
17. Chemical formula of heavy water is __________.
18. Hydrogen is obtained industrially as a by-product during electrolysis of __________.
19. Hydrogen is commercially prepared by the thermal decomposition of
20. Hydrogen burns in air with __________ flame.
21. Density of hydrogen is about of 1/14th of that of __________.
22. The electronegativity of hydrogen is __________.
23. The bond energy of hydrogen is __________.
24. Hydrogen liquefies at __________.
25. Hydrogen freezes at __________.
26. The symbol of hydride ion is __________.
27. Hydrogen burns on ignition in the presence of oxygen to produce __________.
28. Hydrogen reacts on heating with P directly to form __________.
29. The hydrides formed by the combination of non-metals of groups IVA, VA, VIA and VIIA with hydrogen are called __________.
30. LiAlH4 is an example of __________.
31. The atomic weight of heavy hydrogen is __________.
32. __________ is the commonest gas in the atmosphere.
33. The element, which does not make salt like hydride is __________.
Chapter 3
S-Block Elements
1. In s-block elements the outermost orbitals are filled with __________ electrons at the outer most.
2. S-block elements consist of __________.
3. The colour of the flame of potassium is __________.
4. On bunsen flame sodium gives __________.
5. On bunsen flame Potassium gives __________.
6. On bunsen flame Cesium gives __________.
7. On bunsen flame Calsium gives __________.
8. On bunsen flame Strontium gives __________.
9. On bunsen flame Barium gives __________.
10. Alkaline earth metals are relatively __________ reactive than alkali metals.
11. An apparatus used for commercial preparation of sodium is named as __________.
12. Baking soda is also called __________.
13. The radius of K-atom is 2.31A°. The radius of K+ will be __________.
14. Bicarbonate of alkali metals and alkaline earth metals are formed by passing __________ through a solution of the carbonates of alkali metals or a suspension of carbonates of alkaline earth metals in water.
15. Metallic sodium was first obtained by Sir H. Davy in 1807 by the electrolysis of fused __________.
16. Gay Lussac and Thenard in 1811 prepared sodium by reducing sodium hydroxide with __________.
17. The process in which sodium was prepared by distilling sodium carbonate with carbon and a small amount of chalk as a catalyst was introduced by __________.
18. Down’s cell is used for the production of __________.
19. The density of sodium metal is __________.
20. Melting point of sodium is __________.
21. Boiling point of sodium is __________.
22. The annual consumption of NaCl is about __________.
23. __________ percentage of NaCl is present in sea water.
24. __________ percentage of NaCl or Common salt is present in rock salt.
25. Sodium carbonate is generally called __________.
26. Sodium carbonate is prepared by __________.
27. Aqueous solution of sodium carbonate on heating gives sodium carbonate and __________.
28. __________ is medically used for the treatment of hyperacidity in the stomach.
29. In firge extinguishers __________ is used as a source of carbon dioxide.
30. Mixture of sodium bicarbonate and crystals of vegetable acids, e.g. tartaric acid or citric acid is known as __________.
31. Anhydrous sodium carbonate is called __________.
32. Industrial use of sodium carbonate is in the manufacture of __________.
33. __________ is used in the smelting of iron ores of high sulphur content.
34. Sodium Hydroxide is manufactured on large scale by electrolysis of aqueous solution of __________.
35. Nelson’s cells is used for the manufacture of __________.
36. Castner-Kellner Process is used for the production of __________ on industrial scale.
37. The melting point of NaOH is __________.
38. NaOH decomposes into its elements at about __________.
39. Bleaching powder is manufactured by treating lime with chlorine in __________.
40. The colour of bleaching powder is __________.
41. Bleaching powder smells strongly like __________.
42. When bleaching powder is treated with strong solution of ammonia, __________ gas is evolved.
43. Calsium sulphate occurs in nature as dihydrate salt called __________.
44. Gypsum can be prepared by the action of dilute sulphuric acid on __________.
45. At __________ temperature gypsum loses its three fourth of water.
46. Gypsum is sparingly soluble in water. Its solubility increases with rising temperature up to __________.
47. Magnesium sulphate is usually sold as hydrated salt called __________.
48. Epsom salt is prepared from magnesite MgCO3 on boiling with dilute __________.
49. Epsom salt loses six molecules of water at __________.
50. Epsom salt becomes anhydous at __________.
51. Epsom salt is converted into magnesium oxide by heating it with carbon at bout __________.
52. __________ is used in medicine as purgative.
Chapter 4
P-Block Elements
1. The elements, which belong to III-A group to VIII-A group, are called __________.
2. In p-block elements the metallic character __________ down the group.
3. In p-block elements the orbital in the process of completion is __________.
4. Crystalline boron is a hard substance which is __________ in colour.
5. Out of all the elements of group IIIA, the highest Ionization potential is for __________.
6. Boron possesses close resemblance with __________.
7. Orthoboric acid is prepared by the acidification of hot concentrated solution of borax with calculated quantity of __________.
8. In the Hall-Berou.t process for producing aluminium the substance produced at the cathode is __________.
9. Hydrogen gas many be produced by the reaction of aluminium with a concentrated solution of __________.
10. The most widely distributed element in the earth’s crust after oxygen and silicon is __________.
11. Aluminium resists corrosion due to the formation of a coat of __________.
12. Hall’s Process is used for the production of __________.
13. Duralum is an alloy which contains Mg + Cu + __________ + Mn.
14. The group IV-A of the periodic table consists of __________.
15. Diamond has a high refractive index of __________.
16. At 700°C graphite burns in air to form __________.
17. Red lead is commonly known as __________.
18. __________ is the product of thermal decomposition of sodium bicarbonate.
19. Lead Monoxide is a yellow powder and also called __________.
20. Nitrogen, phosphorus, arsenic, antimony and bismuth are the members of the group __________.
21. All members of group VA exhibit maximum oxidation state of __________.
22. The shape of diamond is __________.
23. On an industrial scale nitric acid is prepared by __________.
24. Poisonous gas present in the exhaust fumes of car is __________.
25. The boiling point of nitric acid is __________.
26. The freezing point of nitric acid is __________.
27. Oxygen, sulphur, selenium, tellurium and polonium are the members of group __________.
28. The first four members of the group VI-A are collectively called __________.
29. There are __________ electrons in the valence shell of elements of group VI-A.
30. The maximum valency of oxygen is __________.
31. Oxygen has __________ allotropic forms.
32. The transition temperature of sulphur is __________.
33. X-rays analysis shows that __________ sulphur consists of chains of sulphur atoms.
34. The purest H2S is obtained by passing vapours of sulphur and hydrogen over finely divided __________ at 450°C.
35. __________ was first prepared in the laboratory by Jabir Bin Hayyan.
36. __________ is called king of chemicals.
37. Lead Chamber process is used for the preparation of __________.
38. Contact Process is used for the production of __________.
39. __________ is called Oleum.
40. Freezing point of pure sulphuric acid is __________.
41. Dilute sulphuric acid dissolves many metals with the evolution of __________ and the corresponding sulphates are formed.
42. Formic acid is converted into carbon monoxide by the action of concentrated __________ and heating.
43. Gases such as oxygen, hydrogen, carbon dioxide, chlorine and sulphur dioxide are often dried by bubbling them through __________.
44. Concentrated sulphuric acid absorbs sulphur trioxide forming __________.
45. Carbon is oxidized to __________ in the presence of sulphuric acid.
46. In a process called pickling the metal sheets are soaked in __________ to remove rust or by chemical action.
47. Phosphine may be produced by the action of water on __________.
48. In the refining of petroleum, __________ is employed to remove tarry materials and sulphur compound.
49. In the Ostwald process, the substance which is used to oxidize NH3 is __________.
50. In the periodic table, halogens, namely fluorine, chlorine, bromine, iodine and astatine are placed in group __________.
51. The brown gas formed when metals reduce HNO3 is __________.
52. __________ is used as catalyst in the Contact Process.
Chapter 5
Transition Elements
1. Annual production of antimony being mined in Pakistan is __________.
2. Annual production of Orchro being mined in Pakistan is __________.
3. Annual production of Chromite being mined in Pakistan is __________.
4. Annual production of manganese being mined in Pakistan is __________.
5. Transition elements other than Sc, Y and Ti have density above __________.
6. Due to d-d transition of electrons, Cu2+ ion appears __________ in colour.
7. The colour of Fe3+ ion is __________.
8. The colour of Fe2+ ion is __________.
9. The colour of Cr3+ ion is __________.
10. The colour of Mn3+ ion is __________.
11. The colour of Mn2+ ion is __________.
12. The colour of the fmale of potassium is __________.
13. The magnetic moment is related to the number of unpaired electron ‘n’ by the equation __________.
14. All the 3-d series elements show an oxidation state of __________ in addition to higher oxidation states except Sc.
15. The majority of transition metal’s ion complexes contain __________ ligands surrounding the central octrahedrally.
16. Copper is known since __________.
17. In Pakistan copper mines at Saindak in __________ were first discovered in 1962.
18. It is estimated that the Saindak mines will yield an annual production of __________ tones of copper from its sulphide ore for a period of 16 years on the commencement of production.
19. __________ percentage of total copper metal is obtained from sulphide ore.
20. The colour of copper is __________.
21. Copper becomes __________ when it is heated.
22. Copper melts at __________ °C.
23. Cu2O is __________ in colour.
24. The colour of CuO oxide is __________.
25. When copper is heated in air, then CuO + __________ are formed.
26. Bronze contains __________% Cu and 10% Sn.
27. __________ is prepared in the laboratory by the action of dilute sulphuric acid on cupric oxide or cupric carbonate.
28. __________ is prepared by dissolving metallic silver in warm dilute nitric acid.
29. The highest common oxidation state of chromium is __________.
30. __________ is prepared in the laboratory by the addition of potassium chloride to hot concentrated solution of sodium dichromate.
31. __________ is used an an indicator in silver nitrate titration for the estimation of halide ions.
32. Potassium permanganate oxidizes acid in presence of dilute __________.
33. __________ is used as a disinfectant for purification of water.
34. __________ is used in bleaching paper pulp.
35. The rusting of iron is catalyzed by __________.
36. Conversion of any metal into its oxide by the action of environment is called __________.
37. Rusting of iron is an example of __________.
38. Aluminium resists the process of corrosion due to the formation of __________.
39. An alloy of iron, which contains chromium 18%, nickel 8% and carbon 0.18% is __________.
40. The black image on an exposed and developed photographic film is composed of __________.
41. In photography printing is accomplished by using an emulsion of __________.
42. All transition elements are __________.
43. Iron rust has the composition of __________.
44. When hydrated, Fe2+ ions are __________.
Periodic Classification of Elements
1. In 1913 Moseley, A British physicist, found that a __________ is the fundamental property of an atom.
2. In the modern Periodic table recommended by the International Union of Pure and Applied Chemistry (IUPAC) in 1982, the elements are arranged in the ascending order of __________.
3. Horizontal rows of elements in the periodic table are called __________.
4. The vertical columns of elements arranged in the Periodic table are called __________.
5. In the Modern Periodic Table there are __________ periods.
6. The first period of Modern Periodic Table contains __________elements.
7. Hydrogen lies in __________ Period.
8. Helium lies in __________ Period.
9. All the elements belonging to the second period are __________.
10. Second period contains __________ elements.
11. The elements of the second period of the modern Periodic table are __________.
12. Third period of periodic table contains __________ elements.
13. The elements of the fourth period of the modern periodic table are __________.
14. Fourth period of Modern Periodic Table contains __________ elements.
15. Fifth period of Modern Periodic Table contains __________ elements.
16. Those elements, which have ‘d’ orbitals in the process of completion in the form of ions or atoms, are called __________.
17. Elements in IB group are called __________.
18. Those elements, which involve ‘s’ orbital filling in their valence shells, are called __________.
19. The sixth period of Modern Periodic Table contains __________ elements.
20. The longest period of modern Periodic Table is __________.
21. The eight ‘s’ and ‘p’ block elements in the 4th and 5th periods are known as __________.
22. The elements of group IA and IIA are classified as __________ elements.
23. The seventh period of modern Periodic table contains __________ elements.
24. The elements on the right hand side of the Periodic table are called __________.
25. The outer most shell involved in chemical bonding are called __________.
26. The number of electrons in the outermost or valence shells is called __________.
27. Na2O is strongly __________ in nature.
28. Cl2O7 is strongly __________ in nature.
29. Greater the electronegativity of an element, stronger is the __________ character of its oxide.
30. In case of transition elements, the last electrons are received by __________.
31. Elements in group IB, IIB through VIIB are known as __________.
32. Elements in group IB, IIB through VIIB are known as __________.
33. Elements in the group VI A and __________ are the most active non-metals.
34. The correct order of second ionization potential of carbon, nitrogen, oxygen and fluorine is __________.
35. The elements having seven valence electrons are known as __________.
36. The elements of group IIIA to VIIA are called __________.
37. Maximum number of electrons present in sixth period is __________.
38. The elements of group VIIIA are called __________.
39. In case of inner transition elements the last electrons are received by __________.
40. In case of outer transition elements the last electron are received by __________.
Chapter 2
Hydrogen
1. Hydrogen was first prepared by Cavendish in 1766 by the action of __________.
2. Hydrogen is evolved by the action of cold diluted HNO3 on __________.
3. Hydrogen is found in nature in combined state. The most abundant compound of hydrogen is __________.
4. The electronic configuration of hydrogen atom is __________.
5. Hydrogen forms slat like hydrides with the elements of __________.
6. Hydrogen forms interstitial hydrides with the elements of __________.
7. An example of covalent hydride is __________.
8. Alkali metals need __________ electron to complete their outermost shells.
9. The number of isotopes of hydrogen is __________.
10. 1H1 is symbol of __________.
11. 1H2 is the symbol of __________.
12. 1H3 is the symbol of __________.
13. The number of neutrons in the nuclei of tritium atom is __________.
14. The number of neutrons in the nucleus of protium is __________.
15. The mass number of deutrium is __________.
16. Tritium is present to the extent of one atom in __________ atoms.
17. Chemical formula of heavy water is __________.
18. Hydrogen is obtained industrially as a by-product during electrolysis of __________.
19. Hydrogen is commercially prepared by the thermal decomposition of
20. Hydrogen burns in air with __________ flame.
21. Density of hydrogen is about of 1/14th of that of __________.
22. The electronegativity of hydrogen is __________.
23. The bond energy of hydrogen is __________.
24. Hydrogen liquefies at __________.
25. Hydrogen freezes at __________.
26. The symbol of hydride ion is __________.
27. Hydrogen burns on ignition in the presence of oxygen to produce __________.
28. Hydrogen reacts on heating with P directly to form __________.
29. The hydrides formed by the combination of non-metals of groups IVA, VA, VIA and VIIA with hydrogen are called __________.
30. LiAlH4 is an example of __________.
31. The atomic weight of heavy hydrogen is __________.
32. __________ is the commonest gas in the atmosphere.
33. The element, which does not make salt like hydride is __________.
Chapter 3
S-Block Elements
1. In s-block elements the outermost orbitals are filled with __________ electrons at the outer most.
2. S-block elements consist of __________.
3. The colour of the flame of potassium is __________.
4. On bunsen flame sodium gives __________.
5. On bunsen flame Potassium gives __________.
6. On bunsen flame Cesium gives __________.
7. On bunsen flame Calsium gives __________.
8. On bunsen flame Strontium gives __________.
9. On bunsen flame Barium gives __________.
10. Alkaline earth metals are relatively __________ reactive than alkali metals.
11. An apparatus used for commercial preparation of sodium is named as __________.
12. Baking soda is also called __________.
13. The radius of K-atom is 2.31A°. The radius of K+ will be __________.
14. Bicarbonate of alkali metals and alkaline earth metals are formed by passing __________ through a solution of the carbonates of alkali metals or a suspension of carbonates of alkaline earth metals in water.
15. Metallic sodium was first obtained by Sir H. Davy in 1807 by the electrolysis of fused __________.
16. Gay Lussac and Thenard in 1811 prepared sodium by reducing sodium hydroxide with __________.
17. The process in which sodium was prepared by distilling sodium carbonate with carbon and a small amount of chalk as a catalyst was introduced by __________.
18. Down’s cell is used for the production of __________.
19. The density of sodium metal is __________.
20. Melting point of sodium is __________.
21. Boiling point of sodium is __________.
22. The annual consumption of NaCl is about __________.
23. __________ percentage of NaCl is present in sea water.
24. __________ percentage of NaCl or Common salt is present in rock salt.
25. Sodium carbonate is generally called __________.
26. Sodium carbonate is prepared by __________.
27. Aqueous solution of sodium carbonate on heating gives sodium carbonate and __________.
28. __________ is medically used for the treatment of hyperacidity in the stomach.
29. In firge extinguishers __________ is used as a source of carbon dioxide.
30. Mixture of sodium bicarbonate and crystals of vegetable acids, e.g. tartaric acid or citric acid is known as __________.
31. Anhydrous sodium carbonate is called __________.
32. Industrial use of sodium carbonate is in the manufacture of __________.
33. __________ is used in the smelting of iron ores of high sulphur content.
34. Sodium Hydroxide is manufactured on large scale by electrolysis of aqueous solution of __________.
35. Nelson’s cells is used for the manufacture of __________.
36. Castner-Kellner Process is used for the production of __________ on industrial scale.
37. The melting point of NaOH is __________.
38. NaOH decomposes into its elements at about __________.
39. Bleaching powder is manufactured by treating lime with chlorine in __________.
40. The colour of bleaching powder is __________.
41. Bleaching powder smells strongly like __________.
42. When bleaching powder is treated with strong solution of ammonia, __________ gas is evolved.
43. Calsium sulphate occurs in nature as dihydrate salt called __________.
44. Gypsum can be prepared by the action of dilute sulphuric acid on __________.
45. At __________ temperature gypsum loses its three fourth of water.
46. Gypsum is sparingly soluble in water. Its solubility increases with rising temperature up to __________.
47. Magnesium sulphate is usually sold as hydrated salt called __________.
48. Epsom salt is prepared from magnesite MgCO3 on boiling with dilute __________.
49. Epsom salt loses six molecules of water at __________.
50. Epsom salt becomes anhydous at __________.
51. Epsom salt is converted into magnesium oxide by heating it with carbon at bout __________.
52. __________ is used in medicine as purgative.
Chapter 4
P-Block Elements
1. The elements, which belong to III-A group to VIII-A group, are called __________.
2. In p-block elements the metallic character __________ down the group.
3. In p-block elements the orbital in the process of completion is __________.
4. Crystalline boron is a hard substance which is __________ in colour.
5. Out of all the elements of group IIIA, the highest Ionization potential is for __________.
6. Boron possesses close resemblance with __________.
7. Orthoboric acid is prepared by the acidification of hot concentrated solution of borax with calculated quantity of __________.
8. In the Hall-Berou.t process for producing aluminium the substance produced at the cathode is __________.
9. Hydrogen gas many be produced by the reaction of aluminium with a concentrated solution of __________.
10. The most widely distributed element in the earth’s crust after oxygen and silicon is __________.
11. Aluminium resists corrosion due to the formation of a coat of __________.
12. Hall’s Process is used for the production of __________.
13. Duralum is an alloy which contains Mg + Cu + __________ + Mn.
14. The group IV-A of the periodic table consists of __________.
15. Diamond has a high refractive index of __________.
16. At 700°C graphite burns in air to form __________.
17. Red lead is commonly known as __________.
18. __________ is the product of thermal decomposition of sodium bicarbonate.
19. Lead Monoxide is a yellow powder and also called __________.
20. Nitrogen, phosphorus, arsenic, antimony and bismuth are the members of the group __________.
21. All members of group VA exhibit maximum oxidation state of __________.
22. The shape of diamond is __________.
23. On an industrial scale nitric acid is prepared by __________.
24. Poisonous gas present in the exhaust fumes of car is __________.
25. The boiling point of nitric acid is __________.
26. The freezing point of nitric acid is __________.
27. Oxygen, sulphur, selenium, tellurium and polonium are the members of group __________.
28. The first four members of the group VI-A are collectively called __________.
29. There are __________ electrons in the valence shell of elements of group VI-A.
30. The maximum valency of oxygen is __________.
31. Oxygen has __________ allotropic forms.
32. The transition temperature of sulphur is __________.
33. X-rays analysis shows that __________ sulphur consists of chains of sulphur atoms.
34. The purest H2S is obtained by passing vapours of sulphur and hydrogen over finely divided __________ at 450°C.
35. __________ was first prepared in the laboratory by Jabir Bin Hayyan.
36. __________ is called king of chemicals.
37. Lead Chamber process is used for the preparation of __________.
38. Contact Process is used for the production of __________.
39. __________ is called Oleum.
40. Freezing point of pure sulphuric acid is __________.
41. Dilute sulphuric acid dissolves many metals with the evolution of __________ and the corresponding sulphates are formed.
42. Formic acid is converted into carbon monoxide by the action of concentrated __________ and heating.
43. Gases such as oxygen, hydrogen, carbon dioxide, chlorine and sulphur dioxide are often dried by bubbling them through __________.
44. Concentrated sulphuric acid absorbs sulphur trioxide forming __________.
45. Carbon is oxidized to __________ in the presence of sulphuric acid.
46. In a process called pickling the metal sheets are soaked in __________ to remove rust or by chemical action.
47. Phosphine may be produced by the action of water on __________.
48. In the refining of petroleum, __________ is employed to remove tarry materials and sulphur compound.
49. In the Ostwald process, the substance which is used to oxidize NH3 is __________.
50. In the periodic table, halogens, namely fluorine, chlorine, bromine, iodine and astatine are placed in group __________.
51. The brown gas formed when metals reduce HNO3 is __________.
52. __________ is used as catalyst in the Contact Process.
Chapter 5
Transition Elements
1. Annual production of antimony being mined in Pakistan is __________.
2. Annual production of Orchro being mined in Pakistan is __________.
3. Annual production of Chromite being mined in Pakistan is __________.
4. Annual production of manganese being mined in Pakistan is __________.
5. Transition elements other than Sc, Y and Ti have density above __________.
6. Due to d-d transition of electrons, Cu2+ ion appears __________ in colour.
7. The colour of Fe3+ ion is __________.
8. The colour of Fe2+ ion is __________.
9. The colour of Cr3+ ion is __________.
10. The colour of Mn3+ ion is __________.
11. The colour of Mn2+ ion is __________.
12. The colour of the fmale of potassium is __________.
13. The magnetic moment is related to the number of unpaired electron ‘n’ by the equation __________.
14. All the 3-d series elements show an oxidation state of __________ in addition to higher oxidation states except Sc.
15. The majority of transition metal’s ion complexes contain __________ ligands surrounding the central octrahedrally.
16. Copper is known since __________.
17. In Pakistan copper mines at Saindak in __________ were first discovered in 1962.
18. It is estimated that the Saindak mines will yield an annual production of __________ tones of copper from its sulphide ore for a period of 16 years on the commencement of production.
19. __________ percentage of total copper metal is obtained from sulphide ore.
20. The colour of copper is __________.
21. Copper becomes __________ when it is heated.
22. Copper melts at __________ °C.
23. Cu2O is __________ in colour.
24. The colour of CuO oxide is __________.
25. When copper is heated in air, then CuO + __________ are formed.
26. Bronze contains __________% Cu and 10% Sn.
27. __________ is prepared in the laboratory by the action of dilute sulphuric acid on cupric oxide or cupric carbonate.
28. __________ is prepared by dissolving metallic silver in warm dilute nitric acid.
29. The highest common oxidation state of chromium is __________.
30. __________ is prepared in the laboratory by the addition of potassium chloride to hot concentrated solution of sodium dichromate.
31. __________ is used an an indicator in silver nitrate titration for the estimation of halide ions.
32. Potassium permanganate oxidizes acid in presence of dilute __________.
33. __________ is used as a disinfectant for purification of water.
34. __________ is used in bleaching paper pulp.
35. The rusting of iron is catalyzed by __________.
36. Conversion of any metal into its oxide by the action of environment is called __________.
37. Rusting of iron is an example of __________.
38. Aluminium resists the process of corrosion due to the formation of __________.
39. An alloy of iron, which contains chromium 18%, nickel 8% and carbon 0.18% is __________.
40. The black image on an exposed and developed photographic film is composed of __________.
41. In photography printing is accomplished by using an emulsion of __________.
42. All transition elements are __________.
43. Iron rust has the composition of __________.
44. When hydrated, Fe2+ ions are __________.
Chapter
6
Organic Chemistry
1. The main component of coal is __________.
2. When coal is heated in the absence of air, temperature ranging from __________, it is converted into coke, coal gas and coal tar.
3. The octane number of gasoline may also be increased by ading __________ as knoc inhibitor.
4. In Houdry process the breaking down of long-chain hydrocarbons is accelerated in the presence of a catalyst, made up of a mixture of __________.
5. The process of cracking takes place between temperature __________.
6. Molecular formula of ethers is __________.
7. Alkanes have general formula __________.
8. How many isomers can be obtained from the alkane C6H14.
9. Each alkane differs from its neighbours by __________.
10. The structural formula of ethane is __________.
11. Alkenes have general formula __________.
12. Alkyl halides have general formula __________.
13. On destructive distillation of 1000 kg of coal amount of coal tar formed is __________.
14. Natural gas consist of methane __________.
15. An alkane forms isomers if the number of least carbon atoms is __________.
16. The functional group of alkyle halids is __________.
17. The formula of alkane is __________.
18. The functional group o primary amines is __________.
19. The functional group of ether is __________.
20. The functional group of primary alcohol is __________.
21. The formula of methanol is __________.
22. The formula of ethanol is __________.
23. The formula of propanal is __________.
24. The formula of butanal is __________.
25. Formula of formic acid is __________.
26. The formula of acetic acid is __________.
27. The formula of propnoic acid is __________.
28. The formula of butyric acid is __________.
29. The formula of valeric acid is __________.
30. The formula of capric acid is __________.
31. Phenyl group is represented by __________.
32. The molecular formula of ethane is __________.
Chapter 7
Hydrocarbons
1. An example of alkane is __________.
2. __________ is the smallest hydrocarbon.
3. Natural gas consists of about __________% of methane.
4. A reaction catalyzed by the presence of __________ is called a photochemical reaction.
5. C2H2 reacts with HCl to produce __________.
6. __________ is used as catalyst in the oxidation of methane.
7. Methane reacts with superheated steam, on passing through hot tubes containing a __________ catalyst to yield carbon monoxide and hydrogen.
8. In methane H – C – H bond angles are __________.
9. The structural formula of ethylene is __________.
10. __________ is called ozone.
11. When ethene is passed through a dilute alkaline solution of KMnO4, the pink colour of the solution __________.
12. __________ reagent distinguishes ethylene from acetylene.
13. __________ polymerizes at 100 atmosphere pressure and 400°C to give polyethylene.
14. The polyethene produced in the presence of __________ and titanium tetrachloride as catalyst, shows improvement in its properties such as higher softening temperature, low permeability and greater rigidity.
15. __________ is called Dutch Liquid.
16. General formula of alkynes is __________.
17. __________ is called Acetylene.
18. Carboxylic acids combine with acetylene in the presence of __________ as catalyst, forming vinyl esters and the reaction is termed as Vinylation.
19. When a mixture of acetylene and nitrogen is submitted to an electric discharge, it forms __________.
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20. When acetylene is passed through a copper tube at about 300°C it polymerizes to __________.
21. The brand of synthetic rubber is made by Polymerization of __________.
22. The process in which orbitals of different energies and shapes mix with each other to give equivalent hybrid orbital is called __________.
23. The sp3 signifies that each sp3 orbital is made up of s and p orbitals in the ratio of __________.
24. A molecule of methane has __________sigma bond(s).
25. A molecule of ethane has __________ sigma bond(s).
26. The sp3 hybridization occurs when carbon is bonded to __________ other atoms.
27. Sp2 hybrid orbitals are composed of s and p orbitals in the ratio of __________.
28. __________ bond is weaker.
Chapter 9
Organic Compounds
1. The general formula of alcohol is __________.
2. The general formula of aldehyde is __________.
3. Alcoholic fermentation is brought out by the action of __________.
4. The general formula of carboxylic acid is __________.
5. The general formula of esters is __________.
6. The general formula of ketone is __________.
7. The general formula of ether is __________.
8. The general formula of phenol is __________.
9. Methyl alcohol is used as the starting matrial in the manufacture of __________.
10. The formula of ethyl alcohol is __________.
11. To start the reversibility Estrification we use concentrated __________ used as absorbent of water produced during the reaction.
12. Dehydration means removal of __________.
13. The compound formed when silver powder is ehated with chloform is __________.
14. __________ is used as a fuel for internal combustion engines in many European countries and Brazil.
15. The formula of formaldehyde is __________.
16. The derivatives of carboxylic acids are obtained by replacing the –OH group of the carboxylic group with –OH and __________.
17. The formula of Fehling’s solution is __________.
18. The formula of Iodoform is __________.
19. Melting point of Phenol is __________.
20. Boiling point of Phenol is __________.
21. Phenol when treated with __________, yields both ortho and para sulphonic acids.
22. General formula of Grignard’s Reagent is __________.
23. The formula of Cyanogen chloride is __________.
24. The formula of Chloramine is __________.
Organic Chemistry
1. The main component of coal is __________.
2. When coal is heated in the absence of air, temperature ranging from __________, it is converted into coke, coal gas and coal tar.
3. The octane number of gasoline may also be increased by ading __________ as knoc inhibitor.
4. In Houdry process the breaking down of long-chain hydrocarbons is accelerated in the presence of a catalyst, made up of a mixture of __________.
5. The process of cracking takes place between temperature __________.
6. Molecular formula of ethers is __________.
7. Alkanes have general formula __________.
8. How many isomers can be obtained from the alkane C6H14.
9. Each alkane differs from its neighbours by __________.
10. The structural formula of ethane is __________.
11. Alkenes have general formula __________.
12. Alkyl halides have general formula __________.
13. On destructive distillation of 1000 kg of coal amount of coal tar formed is __________.
14. Natural gas consist of methane __________.
15. An alkane forms isomers if the number of least carbon atoms is __________.
16. The functional group of alkyle halids is __________.
17. The formula of alkane is __________.
18. The functional group o primary amines is __________.
19. The functional group of ether is __________.
20. The functional group of primary alcohol is __________.
21. The formula of methanol is __________.
22. The formula of ethanol is __________.
23. The formula of propanal is __________.
24. The formula of butanal is __________.
25. Formula of formic acid is __________.
26. The formula of acetic acid is __________.
27. The formula of propnoic acid is __________.
28. The formula of butyric acid is __________.
29. The formula of valeric acid is __________.
30. The formula of capric acid is __________.
31. Phenyl group is represented by __________.
32. The molecular formula of ethane is __________.
Chapter 7
Hydrocarbons
1. An example of alkane is __________.
2. __________ is the smallest hydrocarbon.
3. Natural gas consists of about __________% of methane.
4. A reaction catalyzed by the presence of __________ is called a photochemical reaction.
5. C2H2 reacts with HCl to produce __________.
6. __________ is used as catalyst in the oxidation of methane.
7. Methane reacts with superheated steam, on passing through hot tubes containing a __________ catalyst to yield carbon monoxide and hydrogen.
8. In methane H – C – H bond angles are __________.
9. The structural formula of ethylene is __________.
10. __________ is called ozone.
11. When ethene is passed through a dilute alkaline solution of KMnO4, the pink colour of the solution __________.
12. __________ reagent distinguishes ethylene from acetylene.
13. __________ polymerizes at 100 atmosphere pressure and 400°C to give polyethylene.
14. The polyethene produced in the presence of __________ and titanium tetrachloride as catalyst, shows improvement in its properties such as higher softening temperature, low permeability and greater rigidity.
15. __________ is called Dutch Liquid.
16. General formula of alkynes is __________.
17. __________ is called Acetylene.
18. Carboxylic acids combine with acetylene in the presence of __________ as catalyst, forming vinyl esters and the reaction is termed as Vinylation.
19. When a mixture of acetylene and nitrogen is submitted to an electric discharge, it forms __________.
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20. When acetylene is passed through a copper tube at about 300°C it polymerizes to __________.
21. The brand of synthetic rubber is made by Polymerization of __________.
22. The process in which orbitals of different energies and shapes mix with each other to give equivalent hybrid orbital is called __________.
23. The sp3 signifies that each sp3 orbital is made up of s and p orbitals in the ratio of __________.
24. A molecule of methane has __________sigma bond(s).
25. A molecule of ethane has __________ sigma bond(s).
26. The sp3 hybridization occurs when carbon is bonded to __________ other atoms.
27. Sp2 hybrid orbitals are composed of s and p orbitals in the ratio of __________.
28. __________ bond is weaker.
Chapter 9
Organic Compounds
1. The general formula of alcohol is __________.
2. The general formula of aldehyde is __________.
3. Alcoholic fermentation is brought out by the action of __________.
4. The general formula of carboxylic acid is __________.
5. The general formula of esters is __________.
6. The general formula of ketone is __________.
7. The general formula of ether is __________.
8. The general formula of phenol is __________.
9. Methyl alcohol is used as the starting matrial in the manufacture of __________.
10. The formula of ethyl alcohol is __________.
11. To start the reversibility Estrification we use concentrated __________ used as absorbent of water produced during the reaction.
12. Dehydration means removal of __________.
13. The compound formed when silver powder is ehated with chloform is __________.
14. __________ is used as a fuel for internal combustion engines in many European countries and Brazil.
15. The formula of formaldehyde is __________.
16. The derivatives of carboxylic acids are obtained by replacing the –OH group of the carboxylic group with –OH and __________.
17. The formula of Fehling’s solution is __________.
18. The formula of Iodoform is __________.
19. Melting point of Phenol is __________.
20. Boiling point of Phenol is __________.
21. Phenol when treated with __________, yields both ortho and para sulphonic acids.
22. General formula of Grignard’s Reagent is __________.
23. The formula of Cyanogen chloride is __________.
24. The formula of Chloramine is __________.
Chlorine
(Castner-Kellner's)
Introduction
Chlorine plays an important role in industries. Therefore to fulfill the demands, chlorine is manufactured on large scale. It is prepared by the electrolysis of aqueous solution sodium chloride, this process is known as Castner-Kellner's Process and it is carried out in Castner-Kellner's Cell.
Construction of Castner-Kellner's Cell
The Castner-Kellner's cell consist of a steel tank which contain Hg flows from right to left in the cell and is connected with the negative terminal of the battery therefore it acts as cathode. The cell is filled with saturated aqueous solution of NaCl, which also flows in the same direction as Hg. Some graphite rods are dipped into the solution of NaCl. These rods connected with positive terminal of the battery therefore act as anode.
Working Of Castner-Kellner's Cell
When the electric current is passed through the cell. The sodium ion and chloride ion migrates towards their respective electrodes. Chlorine ion moves towards anode, loses its electron and converts into chlorine gas. The free chlorine gas comes out of the tube at the top of the cell. The sodium ion migrates towards cathode gains electrons and converts into sodium metal. The sodium is dissolved in Hg to form sodium amalgum which comes out with the flow of Hg from the cell.
NaCl <----> Na+ + Cl-
Na+ + e- ----> Na0 (At Cathode)
Chemistry XII Viva Notes
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Qs.1 What is salt? What are its two parts?
Ans. Salt is the neutralized product of acid and base. The two essential parts are acidic radical (Anion) and Basic radical (cation).
Qs.2 What is meant by “ion”?
Ans. Ion is an atom with positive or negative change or charges.
Qs.3 What is meant by radical?
Ans. Charged atom or group of atoms. Which exists as a single unit in crystal or in solution form is known as a radical.
Qs.4 What is Acid radical?
Ans. The radical which is contributed by an acid during salt formation and having a negative charge is called acid radical (Anion).
Qs.5 What is basic radical?
Ans. The radical which is contributed by a base during salt formation and having a positive charge is called basic radical (cation).
Qs.6 Why positive radical is called cation?
Ans. On passing the current through a solution it moves towards cathode
Qs.7 Why negative radical is called Anion?
Ans. Negative ions moves towards anode during electrolysis hence they are called Anion.
Qs.8 How the formation of cation and Anion takes place fron an atom?
Ans. When an electron is removed from an atom cation is formed on the other hand when atom gains an electron Anion is formed.
X→ X+ + e- and X + e- X-
Cation Anion
Qs.9 What is meant by group reagent?
Ans. It is the reagent or chemical, used to find out a particular group of cations or Anions.
Qs.10 How many groups are there for Anion?
Ans. There are three main group for Anion.
Qs.11 How many groups are there for cation?
Ans. There are six group for cation.
Qs.12 What are the group reagents for I, II & III group of cation?
Ans. The group reagent for I group is Hcl, Hcl + H2S for II group and NH4Cl +NH4OH are the group reagent for III group.
Qs.13 What are the group reagent for I, II and III of Anion?
Ans. For I group H2SO4 or HCl (dilute) is a group reagent for II groups H2SO4 while III group gives precipitation by Bacl2 or Ammonium molyblate (NH4)2 MoO4.
Qs.14 How the cations of group I, II & III group of Anion?
Ans. The cations of group 1st are precipitated as chlorides, cations of the group at once, hence they are analysised individually e.g.BaCl2 for SO4 2-.
Qs.15 How the cations of group VI are precipitated?
Ans. There is no any specific reagent to precipitate all the cations of the group at once, hence they are analysised individually e.g. BaCl2 for SO4 2-.
Qs.16 What is difference between an “atom” “molecule” and “ion”?
Ans. Atom is the smallest part of an element which can take part in ordinary types of chemical changes. It is electrically neutral because it carries equal number of electrons & protons i.e. two particles of apposite charges. Symbol “Cl” represents a chlorine atom. Molecule is the smallest unit quantity of matter which can exist by itself and contain all the properties of the original substance. A molecule may consists of two similar atoms or two dissimilar atoms. Formula of chlorine “Cl2” represents a chlorine molecule of similar atoms and “NaCl” molecules with two dissimilar atom. Ion It is a charged form of an atom or group of atoms. It carries either a negative or a positive charge according as the number of electrons is greater or lesser than the number of protons present in it. Symbol of chlorine “Cl” represents a negatively charged chlorine atom (Anion) “Cl” while symbol of Ammonium NH4 represents an ammonium ion (cation) “(NH4+)”.
Qs.17 What is the group reagent for cation in group II?
Ans. Hydrogen Sulphate (H2S) in presence of Hydrochloric acid (HCl)
Qs.18 What is Nessler’s reagent and what for its used?
Ans. It is alkaline solution of potassium mercuric iodide K2 (Hgl4). It gives brown precipitation with ammonium salts.
Qs.19 What is chromyl chloride test?
Ans. When solid chloride is heated with potassium dichromate and Conc. Sulphate acid it gives red vapours of chromyl chloride CrO2Cl2.
Qs.20 Which chlorides are in soluble in water?
Ans. AgCl, PbCL2 and Hg2Cl2 salts are in soluble in waters.
Qs.21 What is solubility product?
Ans. It is the product of ionic conc, of the saturated solution of a salt. The Conc, is expressed in moles per liter of the ions.
Qs.22 What do you mean by qualitative analysis?
Ans. It is the process by which the components of a substance or a mixture can be detected
Qs.23 What do you mean by qualitative inorganic analysis?
Ans. It is the process by which the constituent ions of an inorganic Salt can be detected.
Qs.24 What are double salts?
Ans. Those salts whose crystals contain two salts are commonly known as double salts e.g. FeSO4 (NH4)2 SO4. 6H2O
Qs.25 What are complex salts?
Ans. The salts contains a complex cation or Anion in which a transition metal ion has coordinated with a number of electron pair donor e.g. [Fe (CN)6].
Qs.26 What is precipitate (ppt.)?
Ans. It is a compound which separates out in the solid phase from the solution phase on adding a reagent.
Qs.27 Is it possible to use “NaCl” instead of dilute HCl?
Ans. Yes, any soluble chloride can precipitate the radicals of the first group as chloride in cation. The advantage with Hcl is that it does not allow to introduce another basic radical in the solution.
Q.28 Why water and HCl are preferred for the preparation of the original solution (O.S) in the detection of basic radical?
Ans. Because no interference is caused by H2O and HCl while other acids like HNO3 and H2SO4 interfere e.g. Cation like pb2+ , Ca2+ , Sr2+ and Ba2+ form in soluble sulphates with H2SO4 and HNO3 being oxidizing agent interferes in the second groups by oxidizing H2S to S.
Qs.29 What fruity smell indicates?
Ans. The fruity smell is generally due to the formation of an ester. Which indicates the presence of CH3COO ion due to the formation of ethyl acetate CH3COO2H5 or mixed ester fruity smell obtained.
Qs.30 What is meant by water of crystallization give few examples of some compounds?
Ans. The water of crystallization is the molecule of water present in a compound e.g. Copper Sulphate CuSo4 . 5H2O. Magnesium sulphate MgSO4 . 7H2O Barium Chloride Bacl2 . 2H2O etc.
Qs.31 What is functional group?
Ans. It is a group of atoms responsible for their specific properties to the compound possessing it e.g.
i) Carbonyl group > C=O ii) Carboxylic acid group―COOH
iii) Hydroxyl group – OH iv) Amino group – NH2 etc.
Qs.32 What is vinegar?
Ans. Vinegar is a dilute solution of acetic acid. By the smell of which CH2COO- (acetate) ion is confirmed.
Qs.33 Why is testing Cl- radical, When a rod dipped in NH4OH is held over the mouth of test tube, a dense white fumes are produced?
Ans. Because chloride with conc. H2SO4 produce HCl gas which forms white fumes of NH4Cl with NH4OH.
2Cl- + H2SO4 → 2HCl + SO42-
HCl + NH4OH → NH4Cl + H2O
Qs.34 During testing of 2nd group of acidic radicals a brown gas may evolve, which may be due to Br radical or due to NO3 –radical, how will you distinguish them?
Ans. If evolved gas becomes denser on adding MnO2 then it is Br2 gas if it increased by adding copper turnings then it is NO2 gas.
Qs.35 Why in the ring test for Nitrate, a brown ring is formed at the junction of two liquid layers?
Ans. The H2SO4 decompose NO3- radical and evolves “NO” which makes a complex nitro ferrous compound with FeSo4 at the junction which appears as a brown ring.
Qs.36 Why it is necessary to prepare the original solution (O.S) of the salt for the detection of basic radicals except NH4+ radical?
Ans. All the basic radicals are metallic ions except NH4+ therefore they cannot form a volatile substance which can be detected by evolution of a gas by a particular smell. Hence they are detected only by precipitation method from their solution.
Qs.37 Why NH4+ radical can be detected, directly from its salt?
Ans. On testing with an alkali, like NaOH it evolves NH3 gas the smell of which confirms the NH4 radical.
NH4+ + NaOH → NH3 + H2O + Na+
Qs.38 Why the basic radicals are divided into six groups?
Ans. Actually they are divided on the basis of solubility product of their corresponding compounds.
Qs.39 If original solution is prepared in HCl, Why it is concluded that 1st group of basic radicals is absent?
Ans. The first group radicals from in soluble chlorides with HCl, Hence if the solution is clear in HCl it means that 1st group radicals are absent.
Qs.40 Why the ppt of AgCl is soluble in NH4OH?
Ans. Because AgCl is insoluble in water but in the presence of NH4OH it forms a complex diamine compound which can be dissolved easily in water.
Qs.41 What are brisk effervescence?
Ans. Brisk effervescence is due to the evolution of CO2 gas.
Qs.42 How does lime water turn milky on passing CO2 gas through it?
Ans. Lime water turns milky due to the formation of in soluble CaCo3.
Qs.43 What is lime water?
Ans. It is a solution of Ca(OH)2-.
Qs.44 What is slaked lime?
Ans. It is Ca(OH)2-.
Qs.45 What is lime?
Ans. It is calcium oxide CaO.
Qs.46 What is red gas?
Ans. Chromyl chloride is called red gas CrO2Cl2.
Qs.47 What violet vapours indicate?
Ans. They indicate the presence of Iodine.
Qs.48 Mention some cations with their characteristics flames?
Ans. Cations Colour of the flame
Ca2+ Brick red
Sr2+ Deep red
Ba2+ Grassy green
Cu2+ Bluish green
Qs.49 What are crystalline and amorphous salt?
Ans. The salt containing crystals are known as crystalline while powder like salts are called amorphous.
Qs.50 If the salt is coloured what cations may be present?
Ans. If the salt is coloured the following cations may be present
e.g. Cu2+, CO2+, Fe2+, Nl2+, Mn2+ and Fe3+ etc
Qs.51 Give the name of a non-metallic basic radical?
Ans. The non-metallic basic radical is Ammonium NH4+ radical.
Qs.52 In the preparation of original solution for cation. Why H2SO4 is never used?
Ans. Because it is oxidizing agent and precipitate various cation In different groups e.g. Ba2+, Sr2+ and pb2+ are precipitate as sulphate in group II. In this way the whole scheme of cation will disturbe.
Qs.53 Lead may be precipitated in group I as well in group II of cation why?
Ans. In first group PbCl2 is sparingly soluble and hence not all the lead ions Pb2+ are precipitated. Thus the remaining Pb2+ are separated out in group II as Pbs.
Qs.54 What are Alums?
Ans. Alums are the Isomorphous compound.
Qs.55 What are Isomorphous?
Ans. Compounds having the same crystal structures are known as Isomorphous compounds
Qs.56 What is potash alum?
Ans. The hydrated double sulphates salt of potassium and aluminum is known as potash alum e.g. K2SO4Al2 (SO4)3. 24H2O
Qs.57 What are the common uses of potash alum?
Ans. It is used as mordant in dyeing of fabrics sizing of paper as coagulating agent and also for cleaning of water on small scale.
Qs.58 Give the formula for some other Alums?
Ans. Ammonium iron alum (NH4)2 SO4,Fe(SO4)3 . 24H2O
Lithium chromium alum Li2SO4 .Cr2(SO4)3 . 24H2O
Soda alum Na2 SO4 . Al2(SO4)3 . 24H2O
Qs.59 What is the formula of Iodoform give its I.U.P.A.C. name?
Ans. Formula of Iodoform is CHl3 and in IUPAC its name is Tri-Iodomethane.
Qs.60 Give the formula and name of other Haloforms?
Ans. Chloroform CHCl3 and Bromoform CHBr3.
Qs.61 During the preparation of Iodoform temperature should not be higher than 80ºC Why?
Ans. Iodoform may be hydrolyzed above 80ºC.
Introduction
Chlorine plays an important role in industries. Therefore to fulfill the demands, chlorine is manufactured on large scale. It is prepared by the electrolysis of aqueous solution sodium chloride, this process is known as Castner-Kellner's Process and it is carried out in Castner-Kellner's Cell.
Construction of Castner-Kellner's Cell
The Castner-Kellner's cell consist of a steel tank which contain Hg flows from right to left in the cell and is connected with the negative terminal of the battery therefore it acts as cathode. The cell is filled with saturated aqueous solution of NaCl, which also flows in the same direction as Hg. Some graphite rods are dipped into the solution of NaCl. These rods connected with positive terminal of the battery therefore act as anode.
Working Of Castner-Kellner's Cell
When the electric current is passed through the cell. The sodium ion and chloride ion migrates towards their respective electrodes. Chlorine ion moves towards anode, loses its electron and converts into chlorine gas. The free chlorine gas comes out of the tube at the top of the cell. The sodium ion migrates towards cathode gains electrons and converts into sodium metal. The sodium is dissolved in Hg to form sodium amalgum which comes out with the flow of Hg from the cell.
NaCl <----> Na+ + Cl-
Na+ + e- ----> Na0 (At Cathode)
Chemistry XII Viva Notes
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Qs.1 What is salt? What are its two parts?
Ans. Salt is the neutralized product of acid and base. The two essential parts are acidic radical (Anion) and Basic radical (cation).
Qs.2 What is meant by “ion”?
Ans. Ion is an atom with positive or negative change or charges.
Qs.3 What is meant by radical?
Ans. Charged atom or group of atoms. Which exists as a single unit in crystal or in solution form is known as a radical.
Qs.4 What is Acid radical?
Ans. The radical which is contributed by an acid during salt formation and having a negative charge is called acid radical (Anion).
Qs.5 What is basic radical?
Ans. The radical which is contributed by a base during salt formation and having a positive charge is called basic radical (cation).
Qs.6 Why positive radical is called cation?
Ans. On passing the current through a solution it moves towards cathode
Qs.7 Why negative radical is called Anion?
Ans. Negative ions moves towards anode during electrolysis hence they are called Anion.
Qs.8 How the formation of cation and Anion takes place fron an atom?
Ans. When an electron is removed from an atom cation is formed on the other hand when atom gains an electron Anion is formed.
X→ X+ + e- and X + e- X-
Cation Anion
Qs.9 What is meant by group reagent?
Ans. It is the reagent or chemical, used to find out a particular group of cations or Anions.
Qs.10 How many groups are there for Anion?
Ans. There are three main group for Anion.
Qs.11 How many groups are there for cation?
Ans. There are six group for cation.
Qs.12 What are the group reagents for I, II & III group of cation?
Ans. The group reagent for I group is Hcl, Hcl + H2S for II group and NH4Cl +NH4OH are the group reagent for III group.
Qs.13 What are the group reagent for I, II and III of Anion?
Ans. For I group H2SO4 or HCl (dilute) is a group reagent for II groups H2SO4 while III group gives precipitation by Bacl2 or Ammonium molyblate (NH4)2 MoO4.
Qs.14 How the cations of group I, II & III group of Anion?
Ans. The cations of group 1st are precipitated as chlorides, cations of the group at once, hence they are analysised individually e.g.BaCl2 for SO4 2-.
Qs.15 How the cations of group VI are precipitated?
Ans. There is no any specific reagent to precipitate all the cations of the group at once, hence they are analysised individually e.g. BaCl2 for SO4 2-.
Qs.16 What is difference between an “atom” “molecule” and “ion”?
Ans. Atom is the smallest part of an element which can take part in ordinary types of chemical changes. It is electrically neutral because it carries equal number of electrons & protons i.e. two particles of apposite charges. Symbol “Cl” represents a chlorine atom. Molecule is the smallest unit quantity of matter which can exist by itself and contain all the properties of the original substance. A molecule may consists of two similar atoms or two dissimilar atoms. Formula of chlorine “Cl2” represents a chlorine molecule of similar atoms and “NaCl” molecules with two dissimilar atom. Ion It is a charged form of an atom or group of atoms. It carries either a negative or a positive charge according as the number of electrons is greater or lesser than the number of protons present in it. Symbol of chlorine “Cl” represents a negatively charged chlorine atom (Anion) “Cl” while symbol of Ammonium NH4 represents an ammonium ion (cation) “(NH4+)”.
Qs.17 What is the group reagent for cation in group II?
Ans. Hydrogen Sulphate (H2S) in presence of Hydrochloric acid (HCl)
Qs.18 What is Nessler’s reagent and what for its used?
Ans. It is alkaline solution of potassium mercuric iodide K2 (Hgl4). It gives brown precipitation with ammonium salts.
Qs.19 What is chromyl chloride test?
Ans. When solid chloride is heated with potassium dichromate and Conc. Sulphate acid it gives red vapours of chromyl chloride CrO2Cl2.
Qs.20 Which chlorides are in soluble in water?
Ans. AgCl, PbCL2 and Hg2Cl2 salts are in soluble in waters.
Qs.21 What is solubility product?
Ans. It is the product of ionic conc, of the saturated solution of a salt. The Conc, is expressed in moles per liter of the ions.
Qs.22 What do you mean by qualitative analysis?
Ans. It is the process by which the components of a substance or a mixture can be detected
Qs.23 What do you mean by qualitative inorganic analysis?
Ans. It is the process by which the constituent ions of an inorganic Salt can be detected.
Qs.24 What are double salts?
Ans. Those salts whose crystals contain two salts are commonly known as double salts e.g. FeSO4 (NH4)2 SO4. 6H2O
Qs.25 What are complex salts?
Ans. The salts contains a complex cation or Anion in which a transition metal ion has coordinated with a number of electron pair donor e.g. [Fe (CN)6].
Qs.26 What is precipitate (ppt.)?
Ans. It is a compound which separates out in the solid phase from the solution phase on adding a reagent.
Qs.27 Is it possible to use “NaCl” instead of dilute HCl?
Ans. Yes, any soluble chloride can precipitate the radicals of the first group as chloride in cation. The advantage with Hcl is that it does not allow to introduce another basic radical in the solution.
Q.28 Why water and HCl are preferred for the preparation of the original solution (O.S) in the detection of basic radical?
Ans. Because no interference is caused by H2O and HCl while other acids like HNO3 and H2SO4 interfere e.g. Cation like pb2+ , Ca2+ , Sr2+ and Ba2+ form in soluble sulphates with H2SO4 and HNO3 being oxidizing agent interferes in the second groups by oxidizing H2S to S.
Qs.29 What fruity smell indicates?
Ans. The fruity smell is generally due to the formation of an ester. Which indicates the presence of CH3COO ion due to the formation of ethyl acetate CH3COO2H5 or mixed ester fruity smell obtained.
Qs.30 What is meant by water of crystallization give few examples of some compounds?
Ans. The water of crystallization is the molecule of water present in a compound e.g. Copper Sulphate CuSo4 . 5H2O. Magnesium sulphate MgSO4 . 7H2O Barium Chloride Bacl2 . 2H2O etc.
Qs.31 What is functional group?
Ans. It is a group of atoms responsible for their specific properties to the compound possessing it e.g.
i) Carbonyl group > C=O ii) Carboxylic acid group―COOH
iii) Hydroxyl group – OH iv) Amino group – NH2 etc.
Qs.32 What is vinegar?
Ans. Vinegar is a dilute solution of acetic acid. By the smell of which CH2COO- (acetate) ion is confirmed.
Qs.33 Why is testing Cl- radical, When a rod dipped in NH4OH is held over the mouth of test tube, a dense white fumes are produced?
Ans. Because chloride with conc. H2SO4 produce HCl gas which forms white fumes of NH4Cl with NH4OH.
2Cl- + H2SO4 → 2HCl + SO42-
HCl + NH4OH → NH4Cl + H2O
Qs.34 During testing of 2nd group of acidic radicals a brown gas may evolve, which may be due to Br radical or due to NO3 –radical, how will you distinguish them?
Ans. If evolved gas becomes denser on adding MnO2 then it is Br2 gas if it increased by adding copper turnings then it is NO2 gas.
Qs.35 Why in the ring test for Nitrate, a brown ring is formed at the junction of two liquid layers?
Ans. The H2SO4 decompose NO3- radical and evolves “NO” which makes a complex nitro ferrous compound with FeSo4 at the junction which appears as a brown ring.
Qs.36 Why it is necessary to prepare the original solution (O.S) of the salt for the detection of basic radicals except NH4+ radical?
Ans. All the basic radicals are metallic ions except NH4+ therefore they cannot form a volatile substance which can be detected by evolution of a gas by a particular smell. Hence they are detected only by precipitation method from their solution.
Qs.37 Why NH4+ radical can be detected, directly from its salt?
Ans. On testing with an alkali, like NaOH it evolves NH3 gas the smell of which confirms the NH4 radical.
NH4+ + NaOH → NH3 + H2O + Na+
Qs.38 Why the basic radicals are divided into six groups?
Ans. Actually they are divided on the basis of solubility product of their corresponding compounds.
Qs.39 If original solution is prepared in HCl, Why it is concluded that 1st group of basic radicals is absent?
Ans. The first group radicals from in soluble chlorides with HCl, Hence if the solution is clear in HCl it means that 1st group radicals are absent.
Qs.40 Why the ppt of AgCl is soluble in NH4OH?
Ans. Because AgCl is insoluble in water but in the presence of NH4OH it forms a complex diamine compound which can be dissolved easily in water.
Qs.41 What are brisk effervescence?
Ans. Brisk effervescence is due to the evolution of CO2 gas.
Qs.42 How does lime water turn milky on passing CO2 gas through it?
Ans. Lime water turns milky due to the formation of in soluble CaCo3.
Qs.43 What is lime water?
Ans. It is a solution of Ca(OH)2-.
Qs.44 What is slaked lime?
Ans. It is Ca(OH)2-.
Qs.45 What is lime?
Ans. It is calcium oxide CaO.
Qs.46 What is red gas?
Ans. Chromyl chloride is called red gas CrO2Cl2.
Qs.47 What violet vapours indicate?
Ans. They indicate the presence of Iodine.
Qs.48 Mention some cations with their characteristics flames?
Ans. Cations Colour of the flame
Ca2+ Brick red
Sr2+ Deep red
Ba2+ Grassy green
Cu2+ Bluish green
Qs.49 What are crystalline and amorphous salt?
Ans. The salt containing crystals are known as crystalline while powder like salts are called amorphous.
Qs.50 If the salt is coloured what cations may be present?
Ans. If the salt is coloured the following cations may be present
e.g. Cu2+, CO2+, Fe2+, Nl2+, Mn2+ and Fe3+ etc
Qs.51 Give the name of a non-metallic basic radical?
Ans. The non-metallic basic radical is Ammonium NH4+ radical.
Qs.52 In the preparation of original solution for cation. Why H2SO4 is never used?
Ans. Because it is oxidizing agent and precipitate various cation In different groups e.g. Ba2+, Sr2+ and pb2+ are precipitate as sulphate in group II. In this way the whole scheme of cation will disturbe.
Qs.53 Lead may be precipitated in group I as well in group II of cation why?
Ans. In first group PbCl2 is sparingly soluble and hence not all the lead ions Pb2+ are precipitated. Thus the remaining Pb2+ are separated out in group II as Pbs.
Qs.54 What are Alums?
Ans. Alums are the Isomorphous compound.
Qs.55 What are Isomorphous?
Ans. Compounds having the same crystal structures are known as Isomorphous compounds
Qs.56 What is potash alum?
Ans. The hydrated double sulphates salt of potassium and aluminum is known as potash alum e.g. K2SO4Al2 (SO4)3. 24H2O
Qs.57 What are the common uses of potash alum?
Ans. It is used as mordant in dyeing of fabrics sizing of paper as coagulating agent and also for cleaning of water on small scale.
Qs.58 Give the formula for some other Alums?
Ans. Ammonium iron alum (NH4)2 SO4,Fe(SO4)3 . 24H2O
Lithium chromium alum Li2SO4 .Cr2(SO4)3 . 24H2O
Soda alum Na2 SO4 . Al2(SO4)3 . 24H2O
Qs.59 What is the formula of Iodoform give its I.U.P.A.C. name?
Ans. Formula of Iodoform is CHl3 and in IUPAC its name is Tri-Iodomethane.
Qs.60 Give the formula and name of other Haloforms?
Ans. Chloroform CHCl3 and Bromoform CHBr3.
Qs.61 During the preparation of Iodoform temperature should not be higher than 80ºC Why?
Ans. Iodoform may be hydrolyzed above 80ºC.
Qs.62 What is mean by haloform reactions?
Ans. The reaction by which chloroform, bromoform and Iodoform may be prepared .
Ans. The reaction by which chloroform, bromoform and Iodoform may be prepared .
Qs.63 What is the melting point of Iodoform?
Ans. Its melting point is 119ºC.
Qs.64 What types of compounds gives haloform reactions?
Ans. The compounds like methyl ketone, acetaldehyde and ethyl alcohol can give haloform reactions.
Qs.65 What are plastics?
Ans. Plastics are the polymerized products of simple organic molecule or when two or than two simple molecules (Monomer) combine to form a big groups of polymer, it is known as plastic e.g. polythene from ethane. This is a plastic commonly known as polythene i.e.
(C2H4)n = (C2H4)n
Qs.66 What are monomers, polymers and polymerization?
Ans. A large number of simple molecules which may be combine and form a large molecule of high molecular mass are known as “Monomers”, the resulting heavy product is known as the “polymer” and the process of formation of a polymer is known as “polymerization”.
Qs.67 What is P.V.C and P.V.A?
Ans. P.V.C is only poly vinyl chloride plastic and P.V.A is poly vinyl acetate plastic.
Qs.68 What is Bakelite?
Ans. It is a plastic, which is condensation polymer of phenol and formaldehyde.
Qs.69 What is the difference between thermo-plastic & thermo-setting plastics?
Ans. “Thermo-plastics” are those which may be moulded several times by liquefaction without any chemical change e.g. poly vinyl plastic. Where as “Thermo-setting plastic” are those which may be molded once at a time of preparation and become decomposed on heating e.g. Bakelite.
Qs.70 What is the formula of phenol and formaldehyde?
Ans. Phenol is C6H5OH while formaldehyde is HCHO.
Qs.71 What is the formula of Aniline and Iodoform?
Ans. Aniline is C6H5NH2 while Iodoform is CHl3.
Qs.72 What are carbohydrates?
Ans. Carbohydrates are either polyhydroxy aldehydes or ketones or substances which on hydrolysis yield these compounds i.e. polyhydroxy aldehydes or ketones.
Qs.73 Why carbohydrates are also known as hydrates of carbon?
Ans. The general formula of carbohydrates may be Cx(H2O)y i.e. the ratio between hydrogen and oxygen is same as that in water e.g. C6H12O16 Hence they are also known as hydrates of carbon.
Qs.74 Why carbohydrates are also known as saccharides?
Ans. They are also known as saccharides because various carbohydrates gives sweet taste.
Qs.75 What are mono-saccharides?
Ans. Monosaccharides are those carbohydrates which cannot be broken into simpler substances on hydrolysis due to the reason that they consists of single unit of polyhydroxy aldehyde or ketones e.g. glucose and fructose.
Qs.76 What are disaccharides?
Ans. These carbohydrates gives two molecule of monosaccharides on hydrolysis e.g. Maltose, Lactose, and sucrose etc.
Qs.77 What are polysaccharides?
Ans. Those carbohydrates which consists of very large number of monosaccharides units are known as polysaccharides units are known as polysaccharides e.g. starch and cellulose etc.
Qs.78 What is the importance of carbohydrates in living beings?
Ans. Carbohydrates are of major importance to both plants & animals. Human beings use it for many purposes only 65 percent of carbohydrates are used in our diet. It is the chlorophyll in leaves and grass that makes them green, plants gives carbohydrates during the process of photosynthesis. Where plant take CO2 from the air and H2O from the soil and the process occur.
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i.e. 6CO2 + 6H2O = C6H12O6 + 6O2
It may also used in for clothing (Cotton, Rayon, linon) and wood for building burning and making paper.
Qs.79 What are reducing sugars?
Ans. Those carbohydrates which are oxidized by Fehling’s solution and contain free aldehydic group are known as reducing sugar e.g. maltose and glucose etc.
Qs.80 What are non-reducing sugars?
Ans. Those carbohydrates which do not reduce Fehling’s solution by forming red ppt and contain no free aldehydic group are called non-reducing sugars e.g. fructose and sucrose etc.
Qs.81 What is Fehling’s solution?
Ans. It is a mixture of two solution i.e. A & B the solution “A” contains copper sulphate solution while solution “B” contain a solution of sodium potassium tatrate (alkaline medium) along with NoOH.
Qs.82 What is starch?
Ans. Starch is not a single molecule but a mixture of “Amylose” (water soluble, blue colour with iodine) and “Amylopectin” (insoluble in water, violet colour with iodine). The composition of the two is, amylose 10-20% and amylopectin 80-90%.
Qs.83 What is Benedict’s reagent?
Ans. An aqueous solution of cupric sulphate, sodium citrate and sodium carbonate is called Benedict’s reagent.
Qs.84 What is Tollen’s reagent?
Ans. Ammonical silver nitrate solution is known as Tollen’s reagent.
Qs.85 What is Roschell’s salt?
Ans. Sodium potassium tartarate is also known as Roschell’s salt. Which is used in the preparation of Fehling’s soluton.
Qs.86 What are Amino Acids?
Ans. The amino acids that occur in protein all have the – NH2 group and – COOH group attached to the same carbon atom. They are thus alpha amino acids, the carbon atom being the alpha carbon simplest formula by which it can be represent is
H
│
R ― C ― COOH
│
NH2
Qs.87 What are proteins?
Ans. The complex nitrogenous organic compound found in living cell are called proteins which on hydrolysis yield amino acids and these amino acids linked together by a peptide bond.
OR
The polymers of amino acids containing large no of amino acids joined by peptide bond is called protein
Qs.88 What is peptide bond?
O
║
Ans. The acid amide ( - C – NH - ) or the linkage through which amino acids are linked in protein is known as peptide bond.
H O H
│ ║ │
H2N ─── C ── C ─── NH ── C ── COO
│ │
R R
Pipette Bond
Qs.89 What are simple protein?
Ans. The protein on hydrolysis give only simple amino acids are simple proteins e.g. Albumin, glubuiline etc.
Qs.90 What are conjugated proteins?
Ans. Those proteins which on hydrolysis give some other compounds along with amino acids are commonly known as conjugated proteins e.g. phospholecithine
Qs.91 What is meant by derived protein?
Ans. Derived proteins are the products obtained by the action of heat, enzyme or bychemical reaction.
Qs.92 What is the effect of heat on protein and what is the effect of HNO3?
Ans. By heating it coagulates (as in egg) while it becomes yellow by the action of HNO3.
Qs.93 What are fats?
Ans. They are esters of higher fatty acids (palmatic acid, stearic acid, and oleic acid,) with glycerol and the esters are made up of an alcohol part and an acid part.
R – C – OR , C2H6O3
║
O
Acid part Alcohol part
(Mainly glycerol)
Qs.94 Why oils are formed in liquid state at ordinary temperature?
Ans. Oils are in liquid state due to the presence of unsaturated fatty acids in which one OH group of glycerol is esterified.
Qs.95 Why fats are solid at room tempertature?
Ans. Fats are solid because they contain saturated acids with glycerol.
Qs.96 What is the general formula of fats and oils?
Ans. The general formula of fat and oil is as follows.
CH2 ───── OOCR1
│
CH ───── OOCR2
│
CH2 ───── OOCR3
Facts or oil (Here R-may be same or different)
Qs.97 What is the difference between a fat and an oil?
Ans. Fat is a solid at room temperature and contains saturated fatty acids while oil is liquid and contains unsaturated fatty acids.
Qs.98 Write down the name and formula of saturated and unsaturated fatty acids found in fat & oil?
Ans. Palmatic acid C15H31 COOH saturated fattu acid.
Stearic acid C17H35 COOH saturated fatty acid.
Oleic acid C17H33 COOH saturated fatty acid.
.Qs.99 What is the formula of glycerol?
Ans. The formula is
CH2OH
│
CHOH Glycerol
│
CH2OH
Qs.100 What is Saponoifications?
Ans. Hydrolysis of fats or oil by mean of alkali is commonly known as Saponoification.
CH2 – OOC – R1 CH2 – OH ROONa
│ │ │
CH – OOC – R2 + 3NAOH → CH – OH + RCOONa
│ │ │
CH2 – OOC – R3 CH2 – OH RCOONa
Glycerine SOAP
Qs.101 What is soap?
Ans. The sodium or potassium salt of a fatty acid is called a soap e.g.
RCOONa
│
RCOONa Soap
│
RCOONa
Caustic Soda Or NaOH (Castner Kellner's Process)
Introduction
Caustic Soda or Sodium Hydroxide is one of the most important chemicals of industrial use. Caustic Soda must be handled carefully because it is caustic to touch and causes painful burns.
Castner Kellner's Process
Caustic Soda is manufacture by an electrolytic process. This process is carried out in an electrolytic cell known as Castner-Kellner's cell and the process is called Castner-Kellner's Process.
Construction Of Castner-Kellner's Cell
The electrolytic solution is a 25% of NaCl solution. The anode consist of a number of titanium plates whereas cathode is a steam of flowing mercury.
Diagram Coming Soon
Working of Castner-Kellner's Cell
Sodium chloride dissociates in water to give Na+ and Cl- ions are
2NaCl ----> 2Na+ + 2Cl-
The Cl- ions migrate towards titanium plates, it gains electron and convert into chlorine gas.
2Cl- ----> Cl2 + 2e- (Oxidation)
In castner-kellner's process, H+ ions are not easily discharged due to high voltage of H+ ions, on the contrary Na+ ions are easily discharge over mercury surface. The sodium, thus liberated dissolves in mercury forming an amalgam.
2Na+ + 2e- ----> 2Na (Reduction)
Na + Hg ----> Na/Hg (Amalgum)'
The mercury containing dissolved sodium is sent to another chamber called Denuder where sodium reacts with water forming sodium hydroxide and hydrogen. Denuder is packed with graphite blocks as hydrogen is easily liberated over graphite surface.
2Na/Hg + 2H2O ----> 2NaOH + H2 + 2Hg
The mercury is recycled to dissolve more of sodium.
The solution, which flows out from denuder, is a NaOH solution, which is evaporated to dryness
Sodium (Down's Process)
Introduction
On large scale, sodium is manufactured by electrolysis of fused sodium chloride. The process was given by scientist Dawn, therefore, it is called Dawn's Process.
Construction of Down's Cell
A special electrolytic cell known as Dawn's cell is used for the electrolysis of sodium carbonate. The cell consists of a cylindrical shape iron basin lined inside by firebricks. The iron cathode is separated from anode by iron gauze diaphragm. Anode consists of a carbon rod, which is present between two iron cathodes. The electrolytic solution consists of a mixture of sodium chloride (NaCl) and calsium chloride (CaCl2). Calsium Chloride (CaCl2) is added to decrease the melting point of sodium chloride from 801ºC to 600ºC.
Working of Dawn's Cell
When electric current is passed through molten NaCl, the sodium ion migrates towards cathode. It gains and electron and converts into molten sodium metal, which floats inside the cathode compartment. This molten sodium metal is allowed to pass through pipe 'p' which collects it in a vessel 'V' outside the cell
Sodium Carbonate (Ammonia-Solvay Process)
Introduction
Sodium Carbonate is an important compound. It is manufactured by Ammonia-Solvay Process.
Raw Meterials
The raw materials for the manufacture of sodium carbonate are
1. Brine
2. Ammonia, which is made by Haber's Process
3. CO2, CaOH, which are obtained from limestone.
Ammonia-Solvay Process
The Ammonia-Solvay Process consist of the following steps.
Step I - Ammonation of Brine
In first step, ammonia gas is mixed with brine. This process is carried in Ammonation Tower. The ammonation tower consist of mushroom shaped buffels at short intervals. Brine is introduced from the top and ammonia is introduced from bottom. They both flow towards each other. Buffels control the flow of brine and ensure that they are mixed to the point of saturation with ammonia.
Step II - Carbonation of Ammonated Brine
In this step, ammonated brine is mixed with carbon dioxide brine is mixed with carbon dioxide in a tower called carbonating tower or Sonvai tower. Ammonated Brine is fed from the top where as carbon dioxide ascends from the bottom. When these two substances meet, the following chemical reactions takes place.
2NH3 + CO2 + H2O ----> (NH4)2CO3
(NH4)2CO3 + CO2 + H2O ----> 2NH4HCO3
2NH4HCO3 + NaCl ----> NaHCO3 + NH4Cl
Sodium bicarbonate is relatively insoluble, which is precipitated out from the solution by cooling the lower part of the tower. Sodium bicarbonate is separated from soluble ammonium chloride by vacuum filteration.
Step III - Production of Soda Ash
Sodium bicarbonate is heated in a long iron tube to obtain anhydrous sodium carbonate or Soda Ash.
This carbon dioxide is recycled to the solvay tower. This hydrated sodium carbonate is also called washing soda.
Recovery of Ammonia
Ammonia gas is recovered from the remaining solution by treating it with Calsium Hydroxide.
2NH4Cl + Ca(OH)2 ----> CaCl2 + 2H2O + NH3
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Ans. Its melting point is 119ºC.
Qs.64 What types of compounds gives haloform reactions?
Ans. The compounds like methyl ketone, acetaldehyde and ethyl alcohol can give haloform reactions.
Qs.65 What are plastics?
Ans. Plastics are the polymerized products of simple organic molecule or when two or than two simple molecules (Monomer) combine to form a big groups of polymer, it is known as plastic e.g. polythene from ethane. This is a plastic commonly known as polythene i.e.
(C2H4)n = (C2H4)n
Qs.66 What are monomers, polymers and polymerization?
Ans. A large number of simple molecules which may be combine and form a large molecule of high molecular mass are known as “Monomers”, the resulting heavy product is known as the “polymer” and the process of formation of a polymer is known as “polymerization”.
Qs.67 What is P.V.C and P.V.A?
Ans. P.V.C is only poly vinyl chloride plastic and P.V.A is poly vinyl acetate plastic.
Qs.68 What is Bakelite?
Ans. It is a plastic, which is condensation polymer of phenol and formaldehyde.
Qs.69 What is the difference between thermo-plastic & thermo-setting plastics?
Ans. “Thermo-plastics” are those which may be moulded several times by liquefaction without any chemical change e.g. poly vinyl plastic. Where as “Thermo-setting plastic” are those which may be molded once at a time of preparation and become decomposed on heating e.g. Bakelite.
Qs.70 What is the formula of phenol and formaldehyde?
Ans. Phenol is C6H5OH while formaldehyde is HCHO.
Qs.71 What is the formula of Aniline and Iodoform?
Ans. Aniline is C6H5NH2 while Iodoform is CHl3.
Qs.72 What are carbohydrates?
Ans. Carbohydrates are either polyhydroxy aldehydes or ketones or substances which on hydrolysis yield these compounds i.e. polyhydroxy aldehydes or ketones.
Qs.73 Why carbohydrates are also known as hydrates of carbon?
Ans. The general formula of carbohydrates may be Cx(H2O)y i.e. the ratio between hydrogen and oxygen is same as that in water e.g. C6H12O16 Hence they are also known as hydrates of carbon.
Qs.74 Why carbohydrates are also known as saccharides?
Ans. They are also known as saccharides because various carbohydrates gives sweet taste.
Qs.75 What are mono-saccharides?
Ans. Monosaccharides are those carbohydrates which cannot be broken into simpler substances on hydrolysis due to the reason that they consists of single unit of polyhydroxy aldehyde or ketones e.g. glucose and fructose.
Qs.76 What are disaccharides?
Ans. These carbohydrates gives two molecule of monosaccharides on hydrolysis e.g. Maltose, Lactose, and sucrose etc.
Qs.77 What are polysaccharides?
Ans. Those carbohydrates which consists of very large number of monosaccharides units are known as polysaccharides units are known as polysaccharides e.g. starch and cellulose etc.
Qs.78 What is the importance of carbohydrates in living beings?
Ans. Carbohydrates are of major importance to both plants & animals. Human beings use it for many purposes only 65 percent of carbohydrates are used in our diet. It is the chlorophyll in leaves and grass that makes them green, plants gives carbohydrates during the process of photosynthesis. Where plant take CO2 from the air and H2O from the soil and the process occur.
Friendsmania.net
i.e. 6CO2 + 6H2O = C6H12O6 + 6O2
It may also used in for clothing (Cotton, Rayon, linon) and wood for building burning and making paper.
Qs.79 What are reducing sugars?
Ans. Those carbohydrates which are oxidized by Fehling’s solution and contain free aldehydic group are known as reducing sugar e.g. maltose and glucose etc.
Qs.80 What are non-reducing sugars?
Ans. Those carbohydrates which do not reduce Fehling’s solution by forming red ppt and contain no free aldehydic group are called non-reducing sugars e.g. fructose and sucrose etc.
Qs.81 What is Fehling’s solution?
Ans. It is a mixture of two solution i.e. A & B the solution “A” contains copper sulphate solution while solution “B” contain a solution of sodium potassium tatrate (alkaline medium) along with NoOH.
Qs.82 What is starch?
Ans. Starch is not a single molecule but a mixture of “Amylose” (water soluble, blue colour with iodine) and “Amylopectin” (insoluble in water, violet colour with iodine). The composition of the two is, amylose 10-20% and amylopectin 80-90%.
Qs.83 What is Benedict’s reagent?
Ans. An aqueous solution of cupric sulphate, sodium citrate and sodium carbonate is called Benedict’s reagent.
Qs.84 What is Tollen’s reagent?
Ans. Ammonical silver nitrate solution is known as Tollen’s reagent.
Qs.85 What is Roschell’s salt?
Ans. Sodium potassium tartarate is also known as Roschell’s salt. Which is used in the preparation of Fehling’s soluton.
Qs.86 What are Amino Acids?
Ans. The amino acids that occur in protein all have the – NH2 group and – COOH group attached to the same carbon atom. They are thus alpha amino acids, the carbon atom being the alpha carbon simplest formula by which it can be represent is
H
│
R ― C ― COOH
│
NH2
Qs.87 What are proteins?
Ans. The complex nitrogenous organic compound found in living cell are called proteins which on hydrolysis yield amino acids and these amino acids linked together by a peptide bond.
OR
The polymers of amino acids containing large no of amino acids joined by peptide bond is called protein
Qs.88 What is peptide bond?
O
║
Ans. The acid amide ( - C – NH - ) or the linkage through which amino acids are linked in protein is known as peptide bond.
H O H
│ ║ │
H2N ─── C ── C ─── NH ── C ── COO
│ │
R R
Pipette Bond
Qs.89 What are simple protein?
Ans. The protein on hydrolysis give only simple amino acids are simple proteins e.g. Albumin, glubuiline etc.
Qs.90 What are conjugated proteins?
Ans. Those proteins which on hydrolysis give some other compounds along with amino acids are commonly known as conjugated proteins e.g. phospholecithine
Qs.91 What is meant by derived protein?
Ans. Derived proteins are the products obtained by the action of heat, enzyme or bychemical reaction.
Qs.92 What is the effect of heat on protein and what is the effect of HNO3?
Ans. By heating it coagulates (as in egg) while it becomes yellow by the action of HNO3.
Qs.93 What are fats?
Ans. They are esters of higher fatty acids (palmatic acid, stearic acid, and oleic acid,) with glycerol and the esters are made up of an alcohol part and an acid part.
R – C – OR , C2H6O3
║
O
Acid part Alcohol part
(Mainly glycerol)
Qs.94 Why oils are formed in liquid state at ordinary temperature?
Ans. Oils are in liquid state due to the presence of unsaturated fatty acids in which one OH group of glycerol is esterified.
Qs.95 Why fats are solid at room tempertature?
Ans. Fats are solid because they contain saturated acids with glycerol.
Qs.96 What is the general formula of fats and oils?
Ans. The general formula of fat and oil is as follows.
CH2 ───── OOCR1
│
CH ───── OOCR2
│
CH2 ───── OOCR3
Facts or oil (Here R-may be same or different)
Qs.97 What is the difference between a fat and an oil?
Ans. Fat is a solid at room temperature and contains saturated fatty acids while oil is liquid and contains unsaturated fatty acids.
Qs.98 Write down the name and formula of saturated and unsaturated fatty acids found in fat & oil?
Ans. Palmatic acid C15H31 COOH saturated fattu acid.
Stearic acid C17H35 COOH saturated fatty acid.
Oleic acid C17H33 COOH saturated fatty acid.
.Qs.99 What is the formula of glycerol?
Ans. The formula is
CH2OH
│
CHOH Glycerol
│
CH2OH
Qs.100 What is Saponoifications?
Ans. Hydrolysis of fats or oil by mean of alkali is commonly known as Saponoification.
CH2 – OOC – R1 CH2 – OH ROONa
│ │ │
CH – OOC – R2 + 3NAOH → CH – OH + RCOONa
│ │ │
CH2 – OOC – R3 CH2 – OH RCOONa
Glycerine SOAP
Qs.101 What is soap?
Ans. The sodium or potassium salt of a fatty acid is called a soap e.g.
RCOONa
│
RCOONa Soap
│
RCOONa
Caustic Soda Or NaOH (Castner Kellner's Process)
Introduction
Caustic Soda or Sodium Hydroxide is one of the most important chemicals of industrial use. Caustic Soda must be handled carefully because it is caustic to touch and causes painful burns.
Castner Kellner's Process
Caustic Soda is manufacture by an electrolytic process. This process is carried out in an electrolytic cell known as Castner-Kellner's cell and the process is called Castner-Kellner's Process.
Construction Of Castner-Kellner's Cell
The electrolytic solution is a 25% of NaCl solution. The anode consist of a number of titanium plates whereas cathode is a steam of flowing mercury.
Diagram Coming Soon
Working of Castner-Kellner's Cell
Sodium chloride dissociates in water to give Na+ and Cl- ions are
2NaCl ----> 2Na+ + 2Cl-
The Cl- ions migrate towards titanium plates, it gains electron and convert into chlorine gas.
2Cl- ----> Cl2 + 2e- (Oxidation)
In castner-kellner's process, H+ ions are not easily discharged due to high voltage of H+ ions, on the contrary Na+ ions are easily discharge over mercury surface. The sodium, thus liberated dissolves in mercury forming an amalgam.
2Na+ + 2e- ----> 2Na (Reduction)
Na + Hg ----> Na/Hg (Amalgum)'
The mercury containing dissolved sodium is sent to another chamber called Denuder where sodium reacts with water forming sodium hydroxide and hydrogen. Denuder is packed with graphite blocks as hydrogen is easily liberated over graphite surface.
2Na/Hg + 2H2O ----> 2NaOH + H2 + 2Hg
The mercury is recycled to dissolve more of sodium.
The solution, which flows out from denuder, is a NaOH solution, which is evaporated to dryness
Sodium (Down's Process)
Introduction
On large scale, sodium is manufactured by electrolysis of fused sodium chloride. The process was given by scientist Dawn, therefore, it is called Dawn's Process.
Construction of Down's Cell
A special electrolytic cell known as Dawn's cell is used for the electrolysis of sodium carbonate. The cell consists of a cylindrical shape iron basin lined inside by firebricks. The iron cathode is separated from anode by iron gauze diaphragm. Anode consists of a carbon rod, which is present between two iron cathodes. The electrolytic solution consists of a mixture of sodium chloride (NaCl) and calsium chloride (CaCl2). Calsium Chloride (CaCl2) is added to decrease the melting point of sodium chloride from 801ºC to 600ºC.
Working of Dawn's Cell
When electric current is passed through molten NaCl, the sodium ion migrates towards cathode. It gains and electron and converts into molten sodium metal, which floats inside the cathode compartment. This molten sodium metal is allowed to pass through pipe 'p' which collects it in a vessel 'V' outside the cell
Sodium Carbonate (Ammonia-Solvay Process)
Introduction
Sodium Carbonate is an important compound. It is manufactured by Ammonia-Solvay Process.
Raw Meterials
The raw materials for the manufacture of sodium carbonate are
1. Brine
2. Ammonia, which is made by Haber's Process
3. CO2, CaOH, which are obtained from limestone.
Ammonia-Solvay Process
The Ammonia-Solvay Process consist of the following steps.
Step I - Ammonation of Brine
In first step, ammonia gas is mixed with brine. This process is carried in Ammonation Tower. The ammonation tower consist of mushroom shaped buffels at short intervals. Brine is introduced from the top and ammonia is introduced from bottom. They both flow towards each other. Buffels control the flow of brine and ensure that they are mixed to the point of saturation with ammonia.
Step II - Carbonation of Ammonated Brine
In this step, ammonated brine is mixed with carbon dioxide brine is mixed with carbon dioxide in a tower called carbonating tower or Sonvai tower. Ammonated Brine is fed from the top where as carbon dioxide ascends from the bottom. When these two substances meet, the following chemical reactions takes place.
2NH3 + CO2 + H2O ----> (NH4)2CO3
(NH4)2CO3 + CO2 + H2O ----> 2NH4HCO3
2NH4HCO3 + NaCl ----> NaHCO3 + NH4Cl
Sodium bicarbonate is relatively insoluble, which is precipitated out from the solution by cooling the lower part of the tower. Sodium bicarbonate is separated from soluble ammonium chloride by vacuum filteration.
Step III - Production of Soda Ash
Sodium bicarbonate is heated in a long iron tube to obtain anhydrous sodium carbonate or Soda Ash.
This carbon dioxide is recycled to the solvay tower. This hydrated sodium carbonate is also called washing soda.
Recovery of Ammonia
Ammonia gas is recovered from the remaining solution by treating it with Calsium Hydroxide.
2NH4Cl + Ca(OH)2 ----> CaCl2 + 2H2O + NH3
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Nitric Acid (Ostwald's Process)
Introduction
On industrial process three methods are employed for the manufacture of nitric acid. Ostwald's Process uses Ammonia as raw material.
Ostwald's Process
When a mixture of ammonia and air is passed through a catalytic chamber containing electrically heated Platinum Gauze, (NO) nitric oxide is formed. This nitric oxide combines with more oxygen to form nitrogen dioxide (NO2). This gas is then absorbed by water to form nitric acid. The plant used in Ostwald's Process consist of following parts.
1. Catalytic Chamber
A mixture of pure and dry ammonia is passed through a catalytic chamber containing heated (800ºC) platinum, which serves as catalyst. Here ammonia is completely oxidized to nitric oxide.
2. Oxidation Tower
The nitric oxide is passed into oxidation tower where the temperature of gases falls to 200ºC - 250ºC. At this temperature nitric is oxidized to nitrogen dioxide.
2NO + O2 ----> 2NO2
3. Absorption Tower
Now the gases containing NO2 and oxygen are than sent to a series of absorption tower, which is filled with broken quartz and water is showered from top of the tower. Then NO2 reacts with H2O in the presence of oxygen to form HNO3.
4NO2 + 2H2O + O2 ----> $HNO3
Read more: Nitric Acid (Ostwald's Process) http://www.friendsmania.net/forum/2nd-year-chemistry-notes/25793.htm#ixzz34VsjTwH2
Introduction
On industrial process three methods are employed for the manufacture of nitric acid. Ostwald's Process uses Ammonia as raw material.
Ostwald's Process
When a mixture of ammonia and air is passed through a catalytic chamber containing electrically heated Platinum Gauze, (NO) nitric oxide is formed. This nitric oxide combines with more oxygen to form nitrogen dioxide (NO2). This gas is then absorbed by water to form nitric acid. The plant used in Ostwald's Process consist of following parts.
1. Catalytic Chamber
A mixture of pure and dry ammonia is passed through a catalytic chamber containing heated (800ºC) platinum, which serves as catalyst. Here ammonia is completely oxidized to nitric oxide.
2. Oxidation Tower
The nitric oxide is passed into oxidation tower where the temperature of gases falls to 200ºC - 250ºC. At this temperature nitric is oxidized to nitrogen dioxide.
2NO + O2 ----> 2NO2
3. Absorption Tower
Now the gases containing NO2 and oxygen are than sent to a series of absorption tower, which is filled with broken quartz and water is showered from top of the tower. Then NO2 reacts with H2O in the presence of oxygen to form HNO3.
4NO2 + 2H2O + O2 ----> $HNO3
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Sulphuric Acid (Contact Process)
Introduction
On industrial scale two methods are employed for the manufacture of sulphuric acid, the Lead Chamber Process and the Contact Process.
The Contact Process
When a mixture of pure and dry sulphur dioxide and air is passed over a heated catalyst such as Platinum Asbestos, then Sulphur dioxide is oxidized into sulphur trioxide. This gas gives sulphuric acid when treated with water.
The plant used in Contact in Contact Process is composed of following parts.
1. Sulphur and Pyrite Burner
In this part, SO2 is produced by either burning sulphur in air or roasting ores. Like ZnS, PbS, FeS2 in air.
S + O2 ----> SO2
4FeS2 + 11O2 ----> 2Fe2O3 + 8S2
2. Dust Chamber
The SO2 obtained from pyrite burner contains impurities such as unreacted coal, dust, moisture, arsenic compounds etc. These impurities are removed from the gas in dust chamber. In this chamber hot air is blown as a result the heavy particles are removed and unreacted sulphur convert into SO2. Now the gases are passed through a cooling pipe into water chamber.
3. Water Chamber
In this chamber a stream of water is showed on the gas to remove the dust particles. The SO2 gas is now proceed into another chamber, which is known as drying tower.
4. Drying Tower
In drying tower moist SO2 gas is mixed with concentrated H2SO4. As a result the gas become dry and dilute H2SO4 is sink at the bottom.
5. Oxidation Tower
Before oxidation the dry gas is allowed to pass through arsenic purifier containing ferric hydroxide here the arsenic compounds are absorbed. The purified gases are then passed through a strong beam of light to remove any remained dust particle.
The purified and dry SO2 gas is passed through the oxidation tower. This tower consist of iron pipes packed with plantanized asbestos coated with Vanadium Penta Oxide (V2O5), which act as catalyst. In this tower the temperature is kept constant at about 480ºC, under high pressure and high concentration of sulphur dioxide and oxygen, oxidation of SO2 takes place in a favourable condition to yield maximum amount of SO3.
2SO2 + O2 <----> 2SO3 (45000 cal)
6. Absorption Tower
Sulphur trioxide formed in Oxidation Tower is passed up to Absorption tower, where it meets a stream of concentrated sulphuric acid and hence absorbed to form OLEUM. The maximum absorption of sulphur trioxide is 60% at which oleum has maximum density.
SO3 + H2SO4 ----> H2S2O7
Oleum can be diluted to obtain any desired concentration of sulphuric acid.
H2S2O7 + H2O ----> 2H2SO4
Sulphuric acid is obtained from this process is nearly 99.99% pure
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Introduction
On industrial scale two methods are employed for the manufacture of sulphuric acid, the Lead Chamber Process and the Contact Process.
The Contact Process
When a mixture of pure and dry sulphur dioxide and air is passed over a heated catalyst such as Platinum Asbestos, then Sulphur dioxide is oxidized into sulphur trioxide. This gas gives sulphuric acid when treated with water.
The plant used in Contact in Contact Process is composed of following parts.
1. Sulphur and Pyrite Burner
In this part, SO2 is produced by either burning sulphur in air or roasting ores. Like ZnS, PbS, FeS2 in air.
S + O2 ----> SO2
4FeS2 + 11O2 ----> 2Fe2O3 + 8S2
2. Dust Chamber
The SO2 obtained from pyrite burner contains impurities such as unreacted coal, dust, moisture, arsenic compounds etc. These impurities are removed from the gas in dust chamber. In this chamber hot air is blown as a result the heavy particles are removed and unreacted sulphur convert into SO2. Now the gases are passed through a cooling pipe into water chamber.
3. Water Chamber
In this chamber a stream of water is showed on the gas to remove the dust particles. The SO2 gas is now proceed into another chamber, which is known as drying tower.
4. Drying Tower
In drying tower moist SO2 gas is mixed with concentrated H2SO4. As a result the gas become dry and dilute H2SO4 is sink at the bottom.
5. Oxidation Tower
Before oxidation the dry gas is allowed to pass through arsenic purifier containing ferric hydroxide here the arsenic compounds are absorbed. The purified gases are then passed through a strong beam of light to remove any remained dust particle.
The purified and dry SO2 gas is passed through the oxidation tower. This tower consist of iron pipes packed with plantanized asbestos coated with Vanadium Penta Oxide (V2O5), which act as catalyst. In this tower the temperature is kept constant at about 480ºC, under high pressure and high concentration of sulphur dioxide and oxygen, oxidation of SO2 takes place in a favourable condition to yield maximum amount of SO3.
2SO2 + O2 <----> 2SO3 (45000 cal)
6. Absorption Tower
Sulphur trioxide formed in Oxidation Tower is passed up to Absorption tower, where it meets a stream of concentrated sulphuric acid and hence absorbed to form OLEUM. The maximum absorption of sulphur trioxide is 60% at which oleum has maximum density.
SO3 + H2SO4 ----> H2S2O7
Oleum can be diluted to obtain any desired concentration of sulphuric acid.
H2S2O7 + H2O ----> 2H2SO4
Sulphuric acid is obtained from this process is nearly 99.99% pure
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Aluminium (Extraction)
Extraction of Aluminium
Aluminium does not occur free in nature, but it widely distributed in combine state. Aluminium is mainly extracted from Bauxite ore (Al2O3.nH2O). The extraction of Aluminium from Bauxite proceeds through following two steps.
1. Purification of Bauxite to Alumina.
2. Electrolysis of Pure Bauxite (Alumina)
1. Purification of Bauxite
Bauxite contains iron oxide (Fe2O3) and Silica (SiO2) as chief impurites. These impurities must be removed from Bauxite, because they make the aluminium brittle and liable to corrosion. Bauxite ore may be purified by the following methods.
a. Hall's Method
This method is used for the purification of Bauxite containing Fe2O3 and SiO2 as impurities. The finely divided Bauxite is fused with sodium carbonate (Na2CO3), as a result sodium aluminate is formed while the impurities are left unaffected.
Al2O3.nH2O + Na2CO3 ----> 2NaAlO2 + CO2 + nH2O
The fused mass is rapidly extracted with water leaving behind both the impurites Sodium aluminate is heated up to 50ºC - 60ºC in the presence of CO2. As a result while glatinous precipitates of aluminium hydroxide are formed.
The precipitates of Al(OH)3 are separated, washed to remove Na2CO3, dried and ignited about 1500ºC to get pure bauxite (alumina)
b. Bayer's Method
This method is used for the purification of Bauxite containing excess of Fe2O3 as impurity. The finely divided Bauxite is treated with concentrated solution of Sodium Hydroxide. As a result soluble sodium Aluminate is formed, while the impurities are removed by filtering the solution.
Al2O3.nH2O + NaOH ----> 2NaAlO2 + 2(n)H2O
Soluble sodium Aluminate is treated with excess water to form white gatinous precipitates of Aluminium Hydroxide.
2NaAlO2 + 4H2O ----> 2Al(OH)3 + 2NaOH
The precipitates of Al(OH)3 are separated, washed to remove NaOH, dried and ignited about 1500ºC to get pure bauxite (alumina)
c. Serpek's Method
This method is used for the impurities of Bauxite ore containing excess of SiO2 as impurity. The finely divided Bauxite is mixed with carbon and heated up to 1800ºC in the current of Nitrogen. As a result Aluminium Nitride is formed.
2. Electrolysis of Pure Bauxite (Alumina)
The electrolysis of pure bauxite is carried out in a steel tank lined with carbon (graphite). The carbon lining serve as cathode. The anode consist of carbon rods hanging in the molten mass.
In fused state pure alumina is bad conductor of electricity and its melting point is about 2050ºC. So flourspar and cryolite is added in alumina to increase the fluidity of the melt and lower the melting point respectively. When electric current is passed through this mixture, the aluminium is obtained at cathode in liquid state. It sink to bottom from where it drawn, periodically through the tapping hole.
Aluminium produced by this method is 98% and contains traces of Fe, Si and Al2O3 etc.
Refining of Aluminium
The molten aluminium so obtained contains 2% impurities which is further purified by electrolysis in hoop's cell.
Construction
The Hoop's cell consist of an iron box lined with carbon (graphite), the carbon lining served as anode. This iron box consist of three layers, the upper most layer is of pure aluminium the middle layer molten flourides (AlF3, BaF2 and NaF) act as electrolyte, where as the lower layer consist of impure aluminium. The cathode consist of carbon rods hanging in pure aluminium.
Working
When electric current is passed through the impure aluminium goes into the middle layer as all leaving impurities and the pure aluminium is deposited at the top of molten flourides at cathode. The aluminium layer grows and drawn off time to time from tapping hole. The refined Aluminium so obtained is 99.99% pure
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Extraction of Aluminium
Aluminium does not occur free in nature, but it widely distributed in combine state. Aluminium is mainly extracted from Bauxite ore (Al2O3.nH2O). The extraction of Aluminium from Bauxite proceeds through following two steps.
1. Purification of Bauxite to Alumina.
2. Electrolysis of Pure Bauxite (Alumina)
1. Purification of Bauxite
Bauxite contains iron oxide (Fe2O3) and Silica (SiO2) as chief impurites. These impurities must be removed from Bauxite, because they make the aluminium brittle and liable to corrosion. Bauxite ore may be purified by the following methods.
a. Hall's Method
This method is used for the purification of Bauxite containing Fe2O3 and SiO2 as impurities. The finely divided Bauxite is fused with sodium carbonate (Na2CO3), as a result sodium aluminate is formed while the impurities are left unaffected.
Al2O3.nH2O + Na2CO3 ----> 2NaAlO2 + CO2 + nH2O
The fused mass is rapidly extracted with water leaving behind both the impurites Sodium aluminate is heated up to 50ºC - 60ºC in the presence of CO2. As a result while glatinous precipitates of aluminium hydroxide are formed.
The precipitates of Al(OH)3 are separated, washed to remove Na2CO3, dried and ignited about 1500ºC to get pure bauxite (alumina)
b. Bayer's Method
This method is used for the purification of Bauxite containing excess of Fe2O3 as impurity. The finely divided Bauxite is treated with concentrated solution of Sodium Hydroxide. As a result soluble sodium Aluminate is formed, while the impurities are removed by filtering the solution.
Al2O3.nH2O + NaOH ----> 2NaAlO2 + 2(n)H2O
Soluble sodium Aluminate is treated with excess water to form white gatinous precipitates of Aluminium Hydroxide.
2NaAlO2 + 4H2O ----> 2Al(OH)3 + 2NaOH
The precipitates of Al(OH)3 are separated, washed to remove NaOH, dried and ignited about 1500ºC to get pure bauxite (alumina)
c. Serpek's Method
This method is used for the impurities of Bauxite ore containing excess of SiO2 as impurity. The finely divided Bauxite is mixed with carbon and heated up to 1800ºC in the current of Nitrogen. As a result Aluminium Nitride is formed.
2. Electrolysis of Pure Bauxite (Alumina)
The electrolysis of pure bauxite is carried out in a steel tank lined with carbon (graphite). The carbon lining serve as cathode. The anode consist of carbon rods hanging in the molten mass.
In fused state pure alumina is bad conductor of electricity and its melting point is about 2050ºC. So flourspar and cryolite is added in alumina to increase the fluidity of the melt and lower the melting point respectively. When electric current is passed through this mixture, the aluminium is obtained at cathode in liquid state. It sink to bottom from where it drawn, periodically through the tapping hole.
Aluminium produced by this method is 98% and contains traces of Fe, Si and Al2O3 etc.
Refining of Aluminium
The molten aluminium so obtained contains 2% impurities which is further purified by electrolysis in hoop's cell.
Construction
The Hoop's cell consist of an iron box lined with carbon (graphite), the carbon lining served as anode. This iron box consist of three layers, the upper most layer is of pure aluminium the middle layer molten flourides (AlF3, BaF2 and NaF) act as electrolyte, where as the lower layer consist of impure aluminium. The cathode consist of carbon rods hanging in pure aluminium.
Working
When electric current is passed through the impure aluminium goes into the middle layer as all leaving impurities and the pure aluminium is deposited at the top of molten flourides at cathode. The aluminium layer grows and drawn off time to time from tapping hole. The refined Aluminium so obtained is 99.99% pure
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Copper (Extraction)
Extraction Of Copper
Copper is widely distributed in nature. It occurs in free as well as combined state. Blister copper is mainly extracted from sulphide ores (copper pyrite). The extraction of Blister Copper proceeds through following four steps.
Step I - Concentration
The sulphide ores are concentrated by any of the following methods.
a. Gravity Separation
The powdered ore is passed over a wheel so that it falls in two section due to difference in specific gravity.
b. Forth Floatation Process
The finely powdered copper pyrite ore is introduced into water containing Rine oil. The suspension is vigorously agitated with air. The stony matter settles to the bottom and the ore is carried to the top in the forth. The object of this process is to increase the concentration of copper in the ore.
Step II - Heating / Roasting
The concentrated ore is heated strongly (roasted) in a multiple heater roaster (Reverberatory Furnace) in excess of air in order to achieve the following.
1. To remove sulphur as sulphur dioxide.
2. To remove arsenic and antimony as their volatile oxides.
3. To convert the copper pyrite into a mixture of cuprous sulphide and ferrous sulphide.
4. To partially oxidize cuprous sulphide and ferrous sulphide to copper oxide and ferrous oxides respectively.
5. To remove fusible impurities and moisture.
6. To change the ore into porous form.
Step III - Smelting
The roasted ore is mixed with Silica (SiO2) and smelted in a water jacketed blast furnace about 5ft to 6ft high and 1.6 m in diameter. It is a tower like structure made of steel sheet and lined inside with firebricks. A blast of air is necessary for the combustion of ore. This ore is blown through the pipes provided at the base. Since, most of the heat is produced by the combustion of ore itself, therefore, small amount of fuel is required. The cuprous oxide formed during roasting react with unoxidized ferrous sulphide to form cuprous sulphide and ferrous oxide.
CuO + FeS ----> Cu2S + FeO
Silica act as flux, it reacts with ferrous oxide to form fusible slag (Ferrous Silicate) because iron has more affinity for oxygen than copper.
FeO + SiO2 ----> FeSiO3 (Slag)
Slag is removed from the slag hole while a molten mass containing mostly cuprous sulphide, with a very little ferrous sulphide is taken out from the bottom and is called Matte.
Step IV - Bessemerization
The molten is now transferred into Bessemer converter. It is a pear shaped furnace made of steel plates and provides with a basic lining like that of lime or Magnesium Oxide.
Diagram Coming Soon
The main features of this process is that air is blasted through the molten matte. As a result, ferrous sulphide still present gets oxidized to ferrous oxide and is removed as slag. Cuprous sulphide is partially oxidized to oxide, which reacts with remaining cuprous sulphide to form metallic copper.
Cu2S + 2Cu2O ----> 6Cu + SO2↑
The molten copper is run into sand moulds and allowed to solidify. When it gives out absorbed SO2, it leaves blister type appearance at the surface of the metal. The metal thus obtained is known as Blister Copper. It is about 98% pure.
Refining
The crude copper obtained by the above methods contain about 2% of impurities consisting of Fe, Ni, Zn and Ag. It is refined by electrolysis. The process is carried out in a large tank lined with lead. Thick plates of crude copper served as anode and thin plates of pure copper act as cathode. The cathode is coated with oil which helps in easy scraping of pure copper. These electrodes are dipped into electrolytic copper sulphate solution. The electrolysis is then carried out by a current of 1.3 volts. The pure copper is deposited at the cathode while impurities like Fe, Ni, Zn passes into solution and other like Ag and Au fall down as anode mud. During electrolysis following reactions occur.
Cu0 ----> Cu11 + 2e- (At Anode)
Cu11 + 2e- ----> Cu0 (At Cathode)
Copper thus obtained is 99.99% pure and is known as Electrolytic Copper
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Extraction Of Copper
Copper is widely distributed in nature. It occurs in free as well as combined state. Blister copper is mainly extracted from sulphide ores (copper pyrite). The extraction of Blister Copper proceeds through following four steps.
Step I - Concentration
The sulphide ores are concentrated by any of the following methods.
a. Gravity Separation
The powdered ore is passed over a wheel so that it falls in two section due to difference in specific gravity.
b. Forth Floatation Process
The finely powdered copper pyrite ore is introduced into water containing Rine oil. The suspension is vigorously agitated with air. The stony matter settles to the bottom and the ore is carried to the top in the forth. The object of this process is to increase the concentration of copper in the ore.
Step II - Heating / Roasting
The concentrated ore is heated strongly (roasted) in a multiple heater roaster (Reverberatory Furnace) in excess of air in order to achieve the following.
1. To remove sulphur as sulphur dioxide.
2. To remove arsenic and antimony as their volatile oxides.
3. To convert the copper pyrite into a mixture of cuprous sulphide and ferrous sulphide.
4. To partially oxidize cuprous sulphide and ferrous sulphide to copper oxide and ferrous oxides respectively.
5. To remove fusible impurities and moisture.
6. To change the ore into porous form.
Step III - Smelting
The roasted ore is mixed with Silica (SiO2) and smelted in a water jacketed blast furnace about 5ft to 6ft high and 1.6 m in diameter. It is a tower like structure made of steel sheet and lined inside with firebricks. A blast of air is necessary for the combustion of ore. This ore is blown through the pipes provided at the base. Since, most of the heat is produced by the combustion of ore itself, therefore, small amount of fuel is required. The cuprous oxide formed during roasting react with unoxidized ferrous sulphide to form cuprous sulphide and ferrous oxide.
CuO + FeS ----> Cu2S + FeO
Silica act as flux, it reacts with ferrous oxide to form fusible slag (Ferrous Silicate) because iron has more affinity for oxygen than copper.
FeO + SiO2 ----> FeSiO3 (Slag)
Slag is removed from the slag hole while a molten mass containing mostly cuprous sulphide, with a very little ferrous sulphide is taken out from the bottom and is called Matte.
Step IV - Bessemerization
The molten is now transferred into Bessemer converter. It is a pear shaped furnace made of steel plates and provides with a basic lining like that of lime or Magnesium Oxide.
Diagram Coming Soon
The main features of this process is that air is blasted through the molten matte. As a result, ferrous sulphide still present gets oxidized to ferrous oxide and is removed as slag. Cuprous sulphide is partially oxidized to oxide, which reacts with remaining cuprous sulphide to form metallic copper.
Cu2S + 2Cu2O ----> 6Cu + SO2↑
The molten copper is run into sand moulds and allowed to solidify. When it gives out absorbed SO2, it leaves blister type appearance at the surface of the metal. The metal thus obtained is known as Blister Copper. It is about 98% pure.
Refining
The crude copper obtained by the above methods contain about 2% of impurities consisting of Fe, Ni, Zn and Ag. It is refined by electrolysis. The process is carried out in a large tank lined with lead. Thick plates of crude copper served as anode and thin plates of pure copper act as cathode. The cathode is coated with oil which helps in easy scraping of pure copper. These electrodes are dipped into electrolytic copper sulphate solution. The electrolysis is then carried out by a current of 1.3 volts. The pure copper is deposited at the cathode while impurities like Fe, Ni, Zn passes into solution and other like Ag and Au fall down as anode mud. During electrolysis following reactions occur.
Cu0 ----> Cu11 + 2e- (At Anode)
Cu11 + 2e- ----> Cu0 (At Cathode)
Copper thus obtained is 99.99% pure and is known as Electrolytic Copper
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Periodic Table
Mandeleev's Periodic Table
Introduction
In 1969 a Russian chemist studied the properties of elements, on the basis of experimental results, Mendeleev put forwarded a law which is known as periodic law. The periodic law can be stated as
The properties of the elements are the periodic function of their atomic masses.
If the elements are arranged in order to increase atomic masses then similar properties reoccur with definite intervals. Mandeleev arrange the known elements in order to increase atomic masses in the form of table, which is known as Mandeleev's Table. In this table, the elements with similar properties appear in the same vertical column known as groups, the horizontal rows of the elements are called periods.
Advantages of Mandeleev's Periodic Table
Mandeleev's periodic table had a number of advantages over the classification developed till that time.
1. Prediction of New Elements
While arranging the elements in order to increase atomic masses in the table, Mandeleev come across certain positions where no known element was seen fit to him. He left those spaces between vacant and predicted that new elements would be discovered which could be fit in those spaces.
2. Correction of Atomic Masses
At the time of Mandeleev the atomic masses of some elements were not correctly known. Mandeleev's classification of elements help to correct the atomic masses of these elements.
3. Prediction About Properties
Mandeleev also made prediction about the properties of the unknown elements. Many of these predictions were later found correct. He was able to make these prediction because the elements falling in the same group have similar properties.
4. Unication of Elements
Mandeleev's classification co-relates all the elements. The discovery of periodic classification showed that all the elements despite their apparent diversity are co-related with one another and make one systematic whole. Thus, all the elements are unified through a classification.
Periods
There are seven periods (horizontal rows) in the periodic table. The first table period contains two elements that are hydrogen and helium. The second and third periods have eight elements andeach are called short periods. The fourth and fifth periods have eighteen elements each and are called long term. The sixth period contains thirty two elements and is called very long period. The seventh period is incomplete. The properties change gradually within the period or across the table from left to right.
Groups
The vertical columns in the periodic table are called groups or families. There are thirty-two groups or vertical columns in the modern periodic table. There are light groups, which consist of five or six elements and are called main groups, represented by 'A' group, to distinguish them from remaining smaller groups byTransition Elements. The elements of main groups are called Representative Elements or Typical Elements.
The remaining groups that are the short groups of the periodic table are known as transition group. The elements of these groups are collectively called transition elements. These elements are further classified into outer transition elements and inner transition elements. The elements of outer transition elements (d-block) are usually known as 'B' group. The transition elements of 'B' group consist of eight groups and three periods, which are known as a Series. The first series of outer transition elements started from Sc (Scandium) to Zn (Zinc).
The inner transition elements (f-block) consist of two series of elements having fourteen elements each. The first series of inner transition elements is called Lanthanide series and the elements are called Lanthanide's. The second series of inner transition elements is called Actinide series and the elements are called Actinides. The Lanthanide and Actinide are also known as Rear Earth Elements and Heavy Rear Earth Elements respectively.
Blocks of Periodic Table
On the basis of the kind of orbital of elements occupied by the last electron, the periodic table is classified into four blocks.
1. s - Block Elements
Those elements in which the last electron occupies 's' orbital are called s - block of the periodic table. The elements of IA and IIA including hydrogen and helium are called s - Block Elements.
2. p - Block Elements
Those elements in which the last electron occupies 'p' orbital are called p - Block Elements of periodic table. The elements of IIIA to VIIIA (six groups) are p - block elements.
3. d - Block Elements
Those elements in which last electron occupies 'd' orbital are called d - Block Elements. The outer transition elements that is B group (10 groups) belongs to d - block of Periodic Table.
4. f - Block Elements
Those elements in which last electron occupies 'f' orbital are called f - Block Elements. The elements of inner transition (14 groups) that is Lanthanide Series and Actinide Series belongs to f - block elements
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Mandeleev's Periodic Table
Introduction
In 1969 a Russian chemist studied the properties of elements, on the basis of experimental results, Mendeleev put forwarded a law which is known as periodic law. The periodic law can be stated as
The properties of the elements are the periodic function of their atomic masses.
If the elements are arranged in order to increase atomic masses then similar properties reoccur with definite intervals. Mandeleev arrange the known elements in order to increase atomic masses in the form of table, which is known as Mandeleev's Table. In this table, the elements with similar properties appear in the same vertical column known as groups, the horizontal rows of the elements are called periods.
Advantages of Mandeleev's Periodic Table
Mandeleev's periodic table had a number of advantages over the classification developed till that time.
1. Prediction of New Elements
While arranging the elements in order to increase atomic masses in the table, Mandeleev come across certain positions where no known element was seen fit to him. He left those spaces between vacant and predicted that new elements would be discovered which could be fit in those spaces.
2. Correction of Atomic Masses
At the time of Mandeleev the atomic masses of some elements were not correctly known. Mandeleev's classification of elements help to correct the atomic masses of these elements.
3. Prediction About Properties
Mandeleev also made prediction about the properties of the unknown elements. Many of these predictions were later found correct. He was able to make these prediction because the elements falling in the same group have similar properties.
4. Unication of Elements
Mandeleev's classification co-relates all the elements. The discovery of periodic classification showed that all the elements despite their apparent diversity are co-related with one another and make one systematic whole. Thus, all the elements are unified through a classification.
Periods
There are seven periods (horizontal rows) in the periodic table. The first table period contains two elements that are hydrogen and helium. The second and third periods have eight elements andeach are called short periods. The fourth and fifth periods have eighteen elements each and are called long term. The sixth period contains thirty two elements and is called very long period. The seventh period is incomplete. The properties change gradually within the period or across the table from left to right.
Groups
The vertical columns in the periodic table are called groups or families. There are thirty-two groups or vertical columns in the modern periodic table. There are light groups, which consist of five or six elements and are called main groups, represented by 'A' group, to distinguish them from remaining smaller groups byTransition Elements. The elements of main groups are called Representative Elements or Typical Elements.
The remaining groups that are the short groups of the periodic table are known as transition group. The elements of these groups are collectively called transition elements. These elements are further classified into outer transition elements and inner transition elements. The elements of outer transition elements (d-block) are usually known as 'B' group. The transition elements of 'B' group consist of eight groups and three periods, which are known as a Series. The first series of outer transition elements started from Sc (Scandium) to Zn (Zinc).
The inner transition elements (f-block) consist of two series of elements having fourteen elements each. The first series of inner transition elements is called Lanthanide series and the elements are called Lanthanide's. The second series of inner transition elements is called Actinide series and the elements are called Actinides. The Lanthanide and Actinide are also known as Rear Earth Elements and Heavy Rear Earth Elements respectively.
Blocks of Periodic Table
On the basis of the kind of orbital of elements occupied by the last electron, the periodic table is classified into four blocks.
1. s - Block Elements
Those elements in which the last electron occupies 's' orbital are called s - block of the periodic table. The elements of IA and IIA including hydrogen and helium are called s - Block Elements.
2. p - Block Elements
Those elements in which the last electron occupies 'p' orbital are called p - Block Elements of periodic table. The elements of IIIA to VIIIA (six groups) are p - block elements.
3. d - Block Elements
Those elements in which last electron occupies 'd' orbital are called d - Block Elements. The outer transition elements that is B group (10 groups) belongs to d - block of Periodic Table.
4. f - Block Elements
Those elements in which last electron occupies 'f' orbital are called f - Block Elements. The elements of inner transition (14 groups) that is Lanthanide Series and Actinide Series belongs to f - block elements
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Hydrogen
Position of Hydrogen In The Periodic Table
Elements are arranged in the periodic table on the basis of their element configuration. Hydrogen resembles with three groups of periodic table in configuration and properties which are
Group IA (Alkali Metals)
Group IV (Carbon Family)
Group VII A (Halogen)
Hydrogen and Alkali Metals
Similarities
Position of Hydrogen In The Periodic Table
Elements are arranged in the periodic table on the basis of their element configuration. Hydrogen resembles with three groups of periodic table in configuration and properties which are
Group IA (Alkali Metals)
Group IV (Carbon Family)
Group VII A (Halogen)
Hydrogen and Alkali Metals
Similarities
- Both have one electron in valence shell.
- Both are electropositive and form positive ions i.e. H+
and Na+ etc.
- Both are hydrated in aqueous solution as H+, Li+ and
Na+ etc.
- Both reacts with non metals to form similar type of
compounds as H2O, Na2O and HCl, NaCl etc
Dissimilarities
- Hydrogen in gas whereas IA element are metal.
- H+ is unstable whereas Na+, Li+ are stable.
- Alkali metals don't form negative ions but Hydrogen
i.e. H-.
- Hydrogen forms covalent and ionic compounds whereas
alkali metals only form ionic compounds.
- Hydrogen exists as diatomic molecule (H2) where alkali
don't.
- Hydrogen from neutral oxide (H2O) whereas alkali metals
form basic oxides (Na2O).
Hydrogen and Halogens (VII A)
Similarities
- Both are gases i.e. H2, F2, Cl2.
- Both require one electron to complete their shell.
- Both forms negative ions as H-, Cl-, Br-.
- Metallic hydrides (NaH) as well as metallic halides
(NaCl) are ionic.
- Both exists as diatomic molecules i.e. H2, F2, Cl2.
- Both forms covalent compounds with non-metals i.e. CH4,
SiH4, Ccl4.
Dissimilarities
- Hydrogen is colourless whereas halogens are coloured
gases.
- Hydrogen has one electron in valence shell (1s(1)),
whereas halogens have seven electrons (ns2np2).
- Halogens don't form positive ions whereas hydrogen
forms positive ions H+.
- H- is unstable whereas F-, Cl- are stable.
- Hydrogen is reducing agent where halogens are oxidizing
agents.
- Hydrogen forms neutral oxides whereas halogens form
acidic oxides.
Hydrogen and Group IV A
Similarities
- Both have half filled valence shell.
- Both forms covalent compounds.
- Both have same electronegativity.
- Both have same ionization potential.
- Both have same electron affinity.
- Liquid Hydrogen and carbon (except graphite) are bad
conductors.
Dissimilarities
- Hydrogen is gas whereas IV A elements are metals and
metalloids.
- Hydrogen shows mono valency whereas IV shows tetra
valency.
- Hydrogen is in s-block whereas IV A elements are in
p-block.
- Hydrogen has one electron in valence shell whereas IV
A, elements have four.
- Hydrogen does not exhibit allotropy whereas IV A
elements exhibit.
- Hydrogen is diatomic whereas IV A are not.
Conclusion
Due to these similarities and dissimilarities, position of hydrogen is not decided. But it is generally placed with group I A elements due to similar electronic configuration.
Industrial Preparation of Hydrogen
1. Electrolysis of Water
When electricity is passed through water in presence of electro hydrogen and oxygen. H2 is collected at cathode and O2 at anode.
2. From Natural Gas
When a mixture of steam and natural gas is heated upto 900ºC in presence of Nickle, then a mixture of hydrogen and carbon monoxide called water gas is produced.
Separation of H2 From Water Gas
Method I
Calculated amount of steam is mixed with water gas and this mixture is passed over iron oxide or cobate oxide at 500ºC. As a result CO is converted into CO2.
Mixture of CO2 and H2 is passed through water under high pressure. As a result CO2 is converted to H2CO3 leaving free hydrogen gas.
H2O + CO2 + H2 ----> H2CO3 + H2 ↑
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Method II
It is the liquification method in which water gas is cooled up to -200ºC by means of liquid air. Then CO becomes liquid and free hydrogen gas is separated. But this hydrogen may contain traces of CO which are removed by passing it through the solution of NaOH and pure hydrogen is obtained.
3. By the Action of Steam of Coal
When the steam is passed over red hot coke at about 10000ºC then water gas is produced.
Separation of H2 From Water Gas
Method I
Calculated amount of steam is mixed with water gas and this mixture is passed over iron oxide or cobate oxide at 500ºC. As a result CO is converted into CO2.
Mixture of CO2 and H2 is passed through water under high pressure. As a result CO2 is converted to H2CO3 leaving free hydrogen gas.
H2O + CO2 + H2 ----> H2CO3 + H2↑
Method II
It is the liquification method in which water gas is cooled up to -200ºC by means of liquid air. Then CO becomes liquid and free hydrogen gas is separated. But this hydrogen may contain traces of CO which are removed by passing it through the solution of NaOH and pure hydrogen is obtained.
CO + H2 + NaOH ----> HCOONa + H2↑
4. Steam Methanol Process
When mixture of methanol vapours and steam is heated at about 250ºC then a mixture of hydrogen and carbon dioxide is produced.
CH3OH + H2O ----> CO2 + 3H2
This mixture is passed through water under high pressure. As a result, CO2 is converted to H2CO3 leaving free hydrogen gas.
H2O + CO2 + H2 ----> H2CO3 + H2↑
5. Thermal Decomposition of Hydrocarbon
When a hydrocarbon methane is heated at 800ºC in absence of air or oxygen then it is decomposed into carbon black and hydrogen.
This process is called Pyrolysis or Cracking. Carbon Black is used as pigment for inks, plastics, paints, typewriter, carbon papers. It is used in rubber industry, especially as fillers for tyres.
6. Thermal Decomposition of Ammonia
In this process liquid ammonia from cylinders is vaporized and heated to 1000ºC then passed over an active catalyst.
The mixture of N2 and H2 is cooled to -196ºC when N2 liquefies leaving hydrogen free.
Atomic Hydrogen
Definition
The hydrogen obtained as a result of dissociation of ordinary molecular hydrogen is known as Atomic Hydrogen.
Preparation of Atomic Hydrogen
1. Thermal Decomposition of H2
When ordinary hydrogen is heated at 5000ºC in absence of air in a metallic tube of high melting point then it decomposes into atomic hydrogen.
2. Electrical Dissociation of H2
When high voltage electricity is passed through the molecular hydrogen in a discharge tube at low pressure then atomic hydrogen is obtained.
Properties of Atomic Hydrogen
Usually hydrogen is found in molecular form because atomic hydrogen is very reactive. It has only only electron in outermost shell and requires only one electron to complete its shell. Atomic hydrogen gets their electron from other hydrogen atom and form molecular hydrogen. Therefore, its life period is 0.3 seconds. Some reactions of atomic hydrogen are
P + 3H ----> PH3
O2 + 2H ----> H2O2
S + 2H ----> H2S
Cl2 + 2H ----> 2HCl
CuO + 2H ----> Cu + H2O
AgCl + H ----> Ag + HCl
C2H4 + 2H ----> C2H6
Uses of Atomic Hydrogen
Atomic Hydrogen is used to prepare Atomic Hydrogen Torch which contains a temperature of 4000ºC to 5000ºC. It is used to weld all alloys, Nickle steels. Hydrogen gas is passed through electric are set between tungsten filament. H2 decomposes to form atomic hydrogen which then recombines releasing energy due to which temperature is raised to 5000ºC.
H + H ----> H2 + 104 K. Cal
Difference Between Atomic Hydrogen & Nascent Hydrogen
Atomic Hydrogen
1. Produced as a result of dissociation of molecular hydrogen.
2. It is produced by Thermal Decomposition and electrical dissociation of molecular hydrogen.
3. Produced at high temperature.
Nascent Hydrogen
1. Produces at the time of birth in a chemical reaction.
2. It is produced as a result of displacement reaction, when a compound of hydrogen reacts with highly positive metal.
Zn + 2HCl ----> ZnCl2 + 2[H]
3. Produced at room temperature.
Differences between Atomic Hydrogen and Molecular Hydrogen
Atomic Hydrogen
1. Methods of preparation.
2. Reactions are fast.
3. Reactions don't require catalyst.
4. Reactions are carried out at room temperature.
Molecular Hydrogen
1. Methods of preparation.
2. Reactions are slow.
3. Reactions require catalyst.
4. Reactions are carried out at high temperature.
Binary Compounds of Hydrogen
Definition
Compounds of hydrogen with other elements are called binary compounds or Hydrides.
Types of Hydrides
There are six binary compounds of hydrogen which are
1. Ionic Hydrides
There are the hydrides of I A and II A (except Be, Mg)
General Formula = M-H+ (I A)
= M+2 H2- (II A)
Ionic hydrides, metal atom form positive ion and hydrogen atom forms negative ion so they are also called True Hydrides.
Preparation
They are prepared by passing hydrogen gas over hot alkali metals or alkaline earth metals.
Properties
They react with water, acids and alcohol to produce hydrogen gas.
Na+H- + H2O ----> NaOH + H2
Na+H- + HCl ----> NaCl + H2
Na+H- + C2H5OH ----> C2H5ONa + H2
Ca+2H2- + 2H2O ----> Ca(OH)2 + 2H2
2. Covalent Hydrides
These are the hydrides of IV A to VII A. They contain covalent bond, therefore they are called Covalent Hydrides. IV A hydrides are neutral, V A hydrides are basic and VI A, VII A hydrides are basic.
Preparation
They are prepared indirectly as
CaC2 + 2H2O ----> Ca(OH)2 + C2H2
Al4C3 + 6H2O ----> 2Al2O3 + 3CH4
Mg3N2 + 6H2O ----> 3Mg(OH)2 + 2NH3
Ca3P2 + 6H2O ----> 3Ca(OH)2 + 2PH3
PCl3 + 3H2O ----> H3PO3 + 3HCl
3. Complex Hydrides
These are the hydrides of III A being themselves unstable combines with IA hydrides to form complex hydrides.
Preparation
LiH + AlH3 ----> LiAlH4
NaH + BH3 ----> NaBH4
Properties
They are soluble in water and give H2
NaAlH4 ----> Al(OH)3 + NaOH + 4H2
4. Metallic Hydrides
These are the hydrides of transition metals. In these hydrides, H2 occupies interestitial spaces (spaces between the atoms) hence, they are also called Interestitial Hydrides.
Properties of these hydrides are those of the pure metals therefore they are also called Metallic Hydrides.
On strongly heating, they release hydrogen in atomic state. So they are used as catalyst in Hydrogenation reaction.
5. Polymeric Hydrides
These are the hydrides of Be and Mg of IIA which polymerize through hydrogen bonding forming polymers hence they are represented by the formula (BeH2)n and (MgH2)n.
Properties
These properties are intermediate between ionic and covalent hydrides.
6. Broder Line Hydride
These are the hydrides of metals of IB, and few metals of IIIA.
Properties
Their properties are intermediate between metallic and covalent hydrides.
Isotopes of Hydrogen
Atoms of same element having same atomic number but different mass number are called Isotopes. They have same number of protons but different number of neutrons. They have same chemical but different physical properties.
Menzel in 1931 reported that neutral H2 consist of two isotopes, Protium and Deutrium. The third is Tritium which can be obtained by the Artificial Atomic Transmutation.
Protium (IHI or H)
- It is ordinary Hydrogen
- It is most abundant, about 99.98%.
- Atomic Number = 1
- Contians 1 electron, 1 proton and no neutron.
Deutrium (IH2 or D)
- It is also called Heavy Hydrogen
- It occurs about 0.015%.
- Atomic Number = 1, Mass Number = 2
- Contains 1 electron, 1 proton and 1 neutron.
Tritium (IH3 or T)
- It is the heaviest isotope of hydrogen.
- It occurs about 4x10(-15)%.
- It is radioactive. Its half life is 12.5 years.
- Atomic Number = 1, Mass Number = 3.
- Contains 1 electron, 1 proton and 2 neutrons.
Behaviour of H+ and H- with Water
H+ and H- are unstable and don't exist as such in a chemical reaction. H+ exist in water in hydrated from as H904+.
H+ + 4H2O ----> H9O4+
H- ion reacts with water releasing H2 gas.
H- + H2O ----> H2 + OH-
Water Has High Boiling Point
Reason
This is because due to high electronegativity of oxygen atom, water is a highly polar molecule. Due to high polarity strong intermolecular hydrogen bonding develops among water molecule
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Proteins (Short Note)
Definition
Proteins are polymers of amino acids in which different amino acids are linked together through peptide bonds.
Explanation
Proteins consists of one or more polypeptides chain. In general, protein molecules consist of forty to ten thousands or more amino acids units.
The word protein is derived from the Greek word Proteios which means first or of primary importance, in fact proteins are the primary materials of life.
Proteins have very high molecular mass, for e.g. the molecular mass of egg albumin is about 43,000 a.m.u and that of serum albumin is 7,000 a.m.u.
Plants form Proteins from the simple inorganic substances and phosphates. Animals cannot synthesize proteins from inorganic substance. Therfore, they depend upon plants and other animals for dietary Proteins. Animals prepare their own proteins from simple organic molecules. Proteins are necessary for growth and for maintaining existing tissues.
Classification of Proteins
Millions of kinds of proteins exist. The human body may contain as many as five million different kinds of Proteins.
Commonly proteins are classified into the following three classes.
1. Simple Proteins
2. Conjugated Proteins
3. Derived Proteins
1. Simple Proteins
The Proteins which on hydrolysis gave only amino acids or their derivatives, are called simple proteins. They are further classified into following six classes.
a. Albumins
These Proteins are water soluble, and are coagulated by heat. They may be precipitated by saturating their solution with Ammonium Sulphate.
For Example, Egg albumin and serum etc.
b. Globulins
These Proteins are insoluble in water but soluble in dilute salt solution and in dilute solution of strong inorganic acids and basis. They are coagulated by heat.
For Example, Serum Globulins and tissues etc.
c. Prolamins
These Proteins are insoluble in H2O or salt solution, but are soluble in dilute acids and alkalis.
For Example, Zein, Gliadin and Hordein etc.
d. Glutelins
These Proteins are insoluble in water or dilute salt solution but are soluble in the dilute acids and basis. These are coagulated by heat.
For Example, Glutelin and Oryzenin etc.
e. Albuminoids
These Proteins are insoluble in water or salt solution but are soluble in concentrated acids and base.
For example, Keratins and Fibroin etc.
f. Basic Protein
These proteins are strong basic.
For example, Keratins and Fibroin etc.
2. Conjugated Proteins
Those Proteins which contain a non proteinic group attached to the proteinic group are called conjugated proteins. The non proteinic group is called Prosthetic group. This group may be separated from the proteinic part by careful hydrolysis.
Conjugated Proteins are further divided into the following five groups.
a. Nucleo Proteins
The prosthetic group is a nucleic acid. This protein is present in the nuclei of living cell.
b. Chromo Proteins
These are coloured protein. The colour is due to the prosthetic group.
c. Glyco Proteins
In these proteins the prosthetic group contains a carbohydrate or a derivative of carbohydrate.
d. Lipo Proteins
In these proteins prosthetic group is a lipid.
e. Phospho Protein
In these proteins the prosthetic group contains a phosphoric acid.
3. Derived Proteins
The derived proteins are the degradation products obtained by the action of acids, bases or enzymes on proteins. These includes peptones polypeptides and Proteose
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Definition
Proteins are polymers of amino acids in which different amino acids are linked together through peptide bonds.
Explanation
Proteins consists of one or more polypeptides chain. In general, protein molecules consist of forty to ten thousands or more amino acids units.
The word protein is derived from the Greek word Proteios which means first or of primary importance, in fact proteins are the primary materials of life.
Proteins have very high molecular mass, for e.g. the molecular mass of egg albumin is about 43,000 a.m.u and that of serum albumin is 7,000 a.m.u.
Plants form Proteins from the simple inorganic substances and phosphates. Animals cannot synthesize proteins from inorganic substance. Therfore, they depend upon plants and other animals for dietary Proteins. Animals prepare their own proteins from simple organic molecules. Proteins are necessary for growth and for maintaining existing tissues.
Classification of Proteins
Millions of kinds of proteins exist. The human body may contain as many as five million different kinds of Proteins.
Commonly proteins are classified into the following three classes.
1. Simple Proteins
2. Conjugated Proteins
3. Derived Proteins
1. Simple Proteins
The Proteins which on hydrolysis gave only amino acids or their derivatives, are called simple proteins. They are further classified into following six classes.
a. Albumins
These Proteins are water soluble, and are coagulated by heat. They may be precipitated by saturating their solution with Ammonium Sulphate.
For Example, Egg albumin and serum etc.
b. Globulins
These Proteins are insoluble in water but soluble in dilute salt solution and in dilute solution of strong inorganic acids and basis. They are coagulated by heat.
For Example, Serum Globulins and tissues etc.
c. Prolamins
These Proteins are insoluble in H2O or salt solution, but are soluble in dilute acids and alkalis.
For Example, Zein, Gliadin and Hordein etc.
d. Glutelins
These Proteins are insoluble in water or dilute salt solution but are soluble in the dilute acids and basis. These are coagulated by heat.
For Example, Glutelin and Oryzenin etc.
e. Albuminoids
These Proteins are insoluble in water or salt solution but are soluble in concentrated acids and base.
For example, Keratins and Fibroin etc.
f. Basic Protein
These proteins are strong basic.
For example, Keratins and Fibroin etc.
2. Conjugated Proteins
Those Proteins which contain a non proteinic group attached to the proteinic group are called conjugated proteins. The non proteinic group is called Prosthetic group. This group may be separated from the proteinic part by careful hydrolysis.
Conjugated Proteins are further divided into the following five groups.
a. Nucleo Proteins
The prosthetic group is a nucleic acid. This protein is present in the nuclei of living cell.
b. Chromo Proteins
These are coloured protein. The colour is due to the prosthetic group.
c. Glyco Proteins
In these proteins the prosthetic group contains a carbohydrate or a derivative of carbohydrate.
d. Lipo Proteins
In these proteins prosthetic group is a lipid.
e. Phospho Protein
In these proteins the prosthetic group contains a phosphoric acid.
3. Derived Proteins
The derived proteins are the degradation products obtained by the action of acids, bases or enzymes on proteins. These includes peptones polypeptides and Proteose
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Amino Acid (Short Note)
Definition
Amino Acids are the common compounds which contain both carboxylic and amino group.
Carboxylic group is acidic whereas, the amino group is basic.
General Formula
The general formula of amino acid is
R-CNH2H-COOH
Where,
R = alkyl Group
NH2 = Amino Group
COOH = Carboxylic Group
These amino acids are also called α - amino acids because the amino groups is present on α - carbon atom to the carboxylic group.
Classification of Amino Acids
On the basis of number of carboxylic group (-COOH) and amino group (-NH2). Amino acids are classified into the following three classes.
1. Neutral Amino Acids
2. Acidic Amino Acids
3. Basic Amino Acids
1. Neutral Amino Acids
Those amino acids, which have equal number of -COOH and -NH2 groups, are called Neutral Amino Acids.
Example
1. Glycine (CH2NH2COOH)
2. Alanine (CH3-CH-NH2-COOH)
2. Acidic Amino Acids
Those amino acids, which have greater number of -COOH than -NH2 groups are called Acidic Amino Acids.
Example
1. Asparite [CH2NH2CH(COOH)2]
2. Glutamic [HOOC-CH2-CH2-CH-NH2-COOH]
3. Basic Amino Acids
Those amino acids, which cotain greater number of -NH3 than -COOH groups, are called Basic Amino Acids.
Example
1. Lysine [H2N-(CH2)4-CH-NH2-COOH]
Zwitter Ion
When the hydrogen ion of carboxylic group is accepted by amino group in amino acid then Zwitter ion is formed.
Zwitter ion is a German word, its meaning is two charged ion, i.e. both positive and negative charge. This ion is electrically neutral. In solution amino acid, exist in following ionic form.
Peptide Bond Or Peptide Linkage
In the polymers of amino acids, different amino acids are linked together through a bond or linkage, which is known as peptide bond or Peptide bond or Peptide Linkage.
When the hydrogen of amino acid combine with the OH group of other amino acid to form water, the bond between Nitrogen of one amino acid and carbon of other amino acid is formed which is known as Peptide Bond or Linkage. This peptide bond is formed in proteins which are the polymers of amino acids.
Diagram Coming Soon
Essential Amino Acids
Naturally occuring amino acids are known as, essential amino acids.
A large number of sunthetic amino acids are known, but only 20 amino acids occur in nature.
Properties of Amino Acids
The properties of amino acids are as follows.
1. Amino acids are soluble in water, but insoluble in organic solvents.
2. Amino acids are solids.
3. Amino acids have high melting point.
4. They donate or accept proton in the medium in which they are dissolved.
Function of Amino Acids
The role of amino acids in the human body is as follows.
1. Amino Acids can be synthesized back into Proteins.
2. Amino Acids oxidize to provide energy.
3. Amino Acids may be transformed into carbon hydrates or fats
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Definition
Amino Acids are the common compounds which contain both carboxylic and amino group.
Carboxylic group is acidic whereas, the amino group is basic.
General Formula
The general formula of amino acid is
R-CNH2H-COOH
Where,
R = alkyl Group
NH2 = Amino Group
COOH = Carboxylic Group
These amino acids are also called α - amino acids because the amino groups is present on α - carbon atom to the carboxylic group.
Classification of Amino Acids
On the basis of number of carboxylic group (-COOH) and amino group (-NH2). Amino acids are classified into the following three classes.
1. Neutral Amino Acids
2. Acidic Amino Acids
3. Basic Amino Acids
1. Neutral Amino Acids
Those amino acids, which have equal number of -COOH and -NH2 groups, are called Neutral Amino Acids.
Example
1. Glycine (CH2NH2COOH)
2. Alanine (CH3-CH-NH2-COOH)
2. Acidic Amino Acids
Those amino acids, which have greater number of -COOH than -NH2 groups are called Acidic Amino Acids.
Example
1. Asparite [CH2NH2CH(COOH)2]
2. Glutamic [HOOC-CH2-CH2-CH-NH2-COOH]
3. Basic Amino Acids
Those amino acids, which cotain greater number of -NH3 than -COOH groups, are called Basic Amino Acids.
Example
1. Lysine [H2N-(CH2)4-CH-NH2-COOH]
Zwitter Ion
When the hydrogen ion of carboxylic group is accepted by amino group in amino acid then Zwitter ion is formed.
Zwitter ion is a German word, its meaning is two charged ion, i.e. both positive and negative charge. This ion is electrically neutral. In solution amino acid, exist in following ionic form.
Peptide Bond Or Peptide Linkage
In the polymers of amino acids, different amino acids are linked together through a bond or linkage, which is known as peptide bond or Peptide bond or Peptide Linkage.
When the hydrogen of amino acid combine with the OH group of other amino acid to form water, the bond between Nitrogen of one amino acid and carbon of other amino acid is formed which is known as Peptide Bond or Linkage. This peptide bond is formed in proteins which are the polymers of amino acids.
Diagram Coming Soon
Essential Amino Acids
Naturally occuring amino acids are known as, essential amino acids.
A large number of sunthetic amino acids are known, but only 20 amino acids occur in nature.
Properties of Amino Acids
The properties of amino acids are as follows.
1. Amino acids are soluble in water, but insoluble in organic solvents.
2. Amino acids are solids.
3. Amino acids have high melting point.
4. They donate or accept proton in the medium in which they are dissolved.
Function of Amino Acids
The role of amino acids in the human body is as follows.
1. Amino Acids can be synthesized back into Proteins.
2. Amino Acids oxidize to provide energy.
3. Amino Acids may be transformed into carbon hydrates or fats
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Enzymes (Short Note)
Definition
Enzymes are a class of proteins which catalyze all types of bio-chemical reaction, such as digestion, respiration, muscular contraction and metabolism.
In all living structures, the biological reactions are catalyzed by Enzymes, even the biosynthesis of enzymes by living things is also catalyzed by enzymes.
Composition of Enzymes
The composition of enzymes is based on two main components, namely
1. Proteinic Component
2. Non Proteinic Component
1. Proteinic Component
Enzymes are Protein in nature and the proteinic component of enzymes is called Apoenzyme.
2. Non Proteinic Component
Most of the enzymes need a non proteinic component for their activity, which is known as Cofactor. Without Cofactor enzymes cannot show any enzymatic activity. In some enzymes the Cofactor is simply metal ion or organic molecules or ions.
Functions of Enzymes
Enzymes accelerate the rate of reaction as well as drive a reaction to completion, which normally does not occur at room temperature. At the end these are regenerated unchanged. They provide a reaction path way with a lower energy of activation.
Classification of Enzymes
Enzymes are classified into six major classes on the basis of type of reaction it catalyze.
1. Oxido Reductases - Redox Reaction
2. Transferases - Transfer of Group
3. Hydrolases - Hydrolysis Reaction
4. Lyases - Addition Reaction
5. Isomerases - Conversion of Isomers
6. Ligases - Condensation Reaction
Factors Effecting Enzyme Activity
Following are the factors which effect enzyme activity.
1. pH
Every enzyme has its own optimum pH at which it shows maximum activity.
2. Temperature
Every enzyme has its own optimum temperature at which its shows maximum activity. Most of the enzymes show maximum activity between 37ºC - 50ºC.
3. Other Factors
Other factors which effect the enzyme activity are substrate concentration, enzyme concentration and presence of certain ion etc
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Definition
Enzymes are a class of proteins which catalyze all types of bio-chemical reaction, such as digestion, respiration, muscular contraction and metabolism.
In all living structures, the biological reactions are catalyzed by Enzymes, even the biosynthesis of enzymes by living things is also catalyzed by enzymes.
Composition of Enzymes
The composition of enzymes is based on two main components, namely
1. Proteinic Component
2. Non Proteinic Component
1. Proteinic Component
Enzymes are Protein in nature and the proteinic component of enzymes is called Apoenzyme.
2. Non Proteinic Component
Most of the enzymes need a non proteinic component for their activity, which is known as Cofactor. Without Cofactor enzymes cannot show any enzymatic activity. In some enzymes the Cofactor is simply metal ion or organic molecules or ions.
Functions of Enzymes
Enzymes accelerate the rate of reaction as well as drive a reaction to completion, which normally does not occur at room temperature. At the end these are regenerated unchanged. They provide a reaction path way with a lower energy of activation.
Classification of Enzymes
Enzymes are classified into six major classes on the basis of type of reaction it catalyze.
1. Oxido Reductases - Redox Reaction
2. Transferases - Transfer of Group
3. Hydrolases - Hydrolysis Reaction
4. Lyases - Addition Reaction
5. Isomerases - Conversion of Isomers
6. Ligases - Condensation Reaction
Factors Effecting Enzyme Activity
Following are the factors which effect enzyme activity.
1. pH
Every enzyme has its own optimum pH at which it shows maximum activity.
2. Temperature
Every enzyme has its own optimum temperature at which its shows maximum activity. Most of the enzymes show maximum activity between 37ºC - 50ºC.
3. Other Factors
Other factors which effect the enzyme activity are substrate concentration, enzyme concentration and presence of certain ion etc
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Plaster Of Paris (Short Note)
Definition
The hemi hydrate form of calsium sulphate is known as Plaster of Paris.
Molecular Formula
The molecular formula of Plaster of Paris is
CaSO4. 1/2 H2O
Preparation of Plaster of Paris
When Gypsum (CaSO4.2H2O) is heated to about 100ºC, it loses some water of crystallization and is converted to Plaster of Paris.
Uses of Plaster of Paris
1. At high temperatures gypsum loses all the water of crystallization to give anhydrous calsium sulphate.
2. It is used in manufacture of H2SO4.
3. It is used in making of cement.
4. It is used in the preparation of moulds used in surgery and castings
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Definition
The hemi hydrate form of calsium sulphate is known as Plaster of Paris.
Molecular Formula
The molecular formula of Plaster of Paris is
CaSO4. 1/2 H2O
Preparation of Plaster of Paris
When Gypsum (CaSO4.2H2O) is heated to about 100ºC, it loses some water of crystallization and is converted to Plaster of Paris.
Uses of Plaster of Paris
1. At high temperatures gypsum loses all the water of crystallization to give anhydrous calsium sulphate.
2. It is used in manufacture of H2SO4.
3. It is used in making of cement.
4. It is used in the preparation of moulds used in surgery and castings
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Epsom Salt (Short Note)
Definition
The hepta hydrate from of magnesium sulphate is known as Epsom Salt.
Molecular Formula
The molecular formula of Epsom Salt is
MgSO4. 7H2O
Occurance
Magnesium sulphate occurs in nature as Kleserite (MgSO4.H2O)
Preparation of Epsom Salt
Magnesium sulphate is prepared by the reaction of sulphuric acids on Magnesium metal, its oxide, hydroxide or carbonate.
Mg + H2SO4 ----> MgSO4 + H2
MgO + H2SO4 ----> MgSO4 + H2O
Mg(OH)2 + H2SO4 ----> MgSO4 + 2H2O
Mg(OH)2 + H2SO4 ----> MgSO4 + 2H2O
MgCO3 + H2SO4 ----> MgSO4 + H2O + CO2
Properties of Epsom Salt
1. It is soluble in water
2. Crystalline Epsom loses water on heating forming anhydrous magnesium sulphate.
Use of Epsom Salt
Epsom salt is used as a mild purgative
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Definition
The hepta hydrate from of magnesium sulphate is known as Epsom Salt.
Molecular Formula
The molecular formula of Epsom Salt is
MgSO4. 7H2O
Occurance
Magnesium sulphate occurs in nature as Kleserite (MgSO4.H2O)
Preparation of Epsom Salt
Magnesium sulphate is prepared by the reaction of sulphuric acids on Magnesium metal, its oxide, hydroxide or carbonate.
Mg + H2SO4 ----> MgSO4 + H2
MgO + H2SO4 ----> MgSO4 + H2O
Mg(OH)2 + H2SO4 ----> MgSO4 + 2H2O
Mg(OH)2 + H2SO4 ----> MgSO4 + 2H2O
MgCO3 + H2SO4 ----> MgSO4 + H2O + CO2
Properties of Epsom Salt
1. It is soluble in water
2. Crystalline Epsom loses water on heating forming anhydrous magnesium sulphate.
Use of Epsom Salt
Epsom salt is used as a mild purgative
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Pigments (Short Note)
Definition
Pigments are the substances which are used to give the proper colour to paints.
Types of Pigments
Lead forms various types of pigments. Some of them are given below.
1. White lead Pigment
2. Red lead Pigment
3. Chrome Yellow Pigment
4. Chrome Red Pigment
5. Turner's Yellow Pigment
1. White Lead Pigment
White lead Pigment is a basic lead carbonate.
Molecular Formula
[2PbCO3. Pb(OH)2] or [Pb3(OH)2.(CO3)2]
Colour
This lead pigment is white in colour.
Properties
The white colour gradually darken due to the formation of Pbs with Atmospheric H2S. It is also poisonous.
2. Red Lead Pigment (Sandhur)
Molecular Formula
Pb3O4 - Triplumbic Tetra Oxide
2PbO.PbO2 - Lead-Sesqui Oxide
Colour
It is used as red coloured pigment, which varies from orange red to brick red dur to particle size and impurities.
Properties
It is soluble in water but soluble in acids.
3. Chrome Yellow Pigment
Molecular Formula
PbCrO4 - Lead Chromate
It occurs in nature as crocoite.
Colour
It is used as yellow coloured pigment.
Properties
It is insoluble in water but soluble in nitric acid and caustic alkalis.
4. Chrome Red Pigment
Molecular Formula
PbCrO4.PbO - Basic Lead Chromate
Pb2CrO5 - Basic Lead Chromate
Colour
It is used as dark red pigment in paints.
5. Truner's Yellow Pigment
Molecular Formula
PbCl2.4PbO
Other Pigments
Except above pigments, yellow lead monoxide (massicot) and red lead monoxide (litharge or Murda-sang) are also used in paints
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Definition
Pigments are the substances which are used to give the proper colour to paints.
Types of Pigments
Lead forms various types of pigments. Some of them are given below.
1. White lead Pigment
2. Red lead Pigment
3. Chrome Yellow Pigment
4. Chrome Red Pigment
5. Turner's Yellow Pigment
1. White Lead Pigment
White lead Pigment is a basic lead carbonate.
Molecular Formula
[2PbCO3. Pb(OH)2] or [Pb3(OH)2.(CO3)2]
Colour
This lead pigment is white in colour.
Properties
The white colour gradually darken due to the formation of Pbs with Atmospheric H2S. It is also poisonous.
2. Red Lead Pigment (Sandhur)
Molecular Formula
Pb3O4 - Triplumbic Tetra Oxide
2PbO.PbO2 - Lead-Sesqui Oxide
Colour
It is used as red coloured pigment, which varies from orange red to brick red dur to particle size and impurities.
Properties
It is soluble in water but soluble in acids.
3. Chrome Yellow Pigment
Molecular Formula
PbCrO4 - Lead Chromate
It occurs in nature as crocoite.
Colour
It is used as yellow coloured pigment.
Properties
It is insoluble in water but soluble in nitric acid and caustic alkalis.
4. Chrome Red Pigment
Molecular Formula
PbCrO4.PbO - Basic Lead Chromate
Pb2CrO5 - Basic Lead Chromate
Colour
It is used as dark red pigment in paints.
5. Truner's Yellow Pigment
Molecular Formula
PbCl2.4PbO
Other Pigments
Except above pigments, yellow lead monoxide (massicot) and red lead monoxide (litharge or Murda-sang) are also used in paints
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Tin Plating (Short Note)
Definition
The art of coating a metal with tin is called Tin-Plating.
Those metals which are coated with tin are called tin-plated metals.
Purpose And Examples of Tin Plating
The purpose of tin plating is to protect metals from corrosion and food poisoning. Iron is often tin-plated to protect it from rusting. The common cooking oil containers are made of tin-plated iron. The household utensils of copper and brass are tarnished in moist air due to the formation of thin layer of oxides and carbonates of copper. These are poisonous, due to these problems, utensils are coated with tin.
Method of Tin Plating
Tin plating is carried out by the following methods.
1. Hot Dipping or Mechanical Method
In this method, clean iron or steel sheets are dipped in the bath of molten tin. A layer of tin accumulates on the iron sheet and it gets coated.
2. Electrolytic Method or Electro-Plating
This method is based on electrolytic process. An electrolytic cell is developed, which contains metals to be tin-plated as cathode and pure tin as anode. The electrolytic solution consists of salt of tin such as tin chloride or tin sulphate and an acid such as hydrochloric acid. On passing electric current through the electrolytic cell tin deposits on the metal sheet. Through this method a uniform layer of tin is coated on zinc.
3. Classical Method
In this method, the clean hot surface of a utensil is polished with tin metal with a rag. Copper and Brass utensils are tin-plated by this method. The utensils are heated and rubbed with ammonium chloride before they are tin plated. This is done to remove the oxide from the utensils.
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Definition
The art of coating a metal with tin is called Tin-Plating.
Those metals which are coated with tin are called tin-plated metals.
Purpose And Examples of Tin Plating
The purpose of tin plating is to protect metals from corrosion and food poisoning. Iron is often tin-plated to protect it from rusting. The common cooking oil containers are made of tin-plated iron. The household utensils of copper and brass are tarnished in moist air due to the formation of thin layer of oxides and carbonates of copper. These are poisonous, due to these problems, utensils are coated with tin.
Method of Tin Plating
Tin plating is carried out by the following methods.
1. Hot Dipping or Mechanical Method
In this method, clean iron or steel sheets are dipped in the bath of molten tin. A layer of tin accumulates on the iron sheet and it gets coated.
2. Electrolytic Method or Electro-Plating
This method is based on electrolytic process. An electrolytic cell is developed, which contains metals to be tin-plated as cathode and pure tin as anode. The electrolytic solution consists of salt of tin such as tin chloride or tin sulphate and an acid such as hydrochloric acid. On passing electric current through the electrolytic cell tin deposits on the metal sheet. Through this method a uniform layer of tin is coated on zinc.
3. Classical Method
In this method, the clean hot surface of a utensil is polished with tin metal with a rag. Copper and Brass utensils are tin-plated by this method. The utensils are heated and rubbed with ammonium chloride before they are tin plated. This is done to remove the oxide from the utensils.
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Corrosion (Short Note)
Definition
Corrosion is the deterioration of a metal, as a result of its reactions with the environment or any chemical agent.
It is an oxidation process that occurs at the surface of the metal.
Causes of Corrosion
Corrosion may be regarded as the natural tendency of metals to return to their oxidized state. The main causes of corrosion are as follows.
1. The atomosphere
2. Submersion in water
3. Underground Soil Attack
4. Emersion in chemicals
5. Corrosive gases
The most important of these is the atmosphere.
Examples of Corrosion
Some familiar examples of corrosion are as follows.
1. Rusting of Iron
2. Detarnishing of silver
3. Development of green coating on copper, brass and bronze.
Types of Corrosion
There are two types of corrosion.
1. Atmospheric Corrosion
When corrosion in metal is due to the action of atmosphere, it is known as atmospheric corrosion.
2. Corrosion in Liquid
When corrosion in metal is due to the reaction of a liquid on a metal, it is known as corrosion in liquid.
Rate of Corrosion
Corrosion is a chemical process. Different metals corrode at different rates. Gold does not corrode at all. Iron corrodes slowly. Tin, lead, copper and silver corrode very slowly.
Prevention From Corrosion
Corrosion causes great damages to metallic articles such as bridges, ships and vehicles. It has been found out that due to corrosion, one fifth of iron is lost annually. Therefore, any one of the following methods are adopted to prevent corrosion.
1. Protective Metallic Coating
In this method, the metal is coated with a thin layer of less oxidizing metal, which reduces the rate of corrosion. For example, corrosion of iron is prevented by coating it with zinc, tin or chromium.
2. Non-Metallic Material Coating
In this method, the metal is coated with a thin layer of non metallic material such as paints, oils, grease, plastic emulsion, enamels etc. For example, red lead (Pb3O4) and zinc chromate (ZnCrO4) are often used for this purpose.
3. Alloying of Metals
Metals can be made more reistant against corrosion by making their alloys. For example, stainless steal is an alloy of Fe, Cr and Ni.
4. Electro-Plating
Noble and bare metals are used for Electro-Plating on any desired metal.
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Definition
Corrosion is the deterioration of a metal, as a result of its reactions with the environment or any chemical agent.
It is an oxidation process that occurs at the surface of the metal.
Causes of Corrosion
Corrosion may be regarded as the natural tendency of metals to return to their oxidized state. The main causes of corrosion are as follows.
1. The atomosphere
2. Submersion in water
3. Underground Soil Attack
4. Emersion in chemicals
5. Corrosive gases
The most important of these is the atmosphere.
Examples of Corrosion
Some familiar examples of corrosion are as follows.
1. Rusting of Iron
2. Detarnishing of silver
3. Development of green coating on copper, brass and bronze.
Types of Corrosion
There are two types of corrosion.
1. Atmospheric Corrosion
When corrosion in metal is due to the action of atmosphere, it is known as atmospheric corrosion.
2. Corrosion in Liquid
When corrosion in metal is due to the reaction of a liquid on a metal, it is known as corrosion in liquid.
Rate of Corrosion
Corrosion is a chemical process. Different metals corrode at different rates. Gold does not corrode at all. Iron corrodes slowly. Tin, lead, copper and silver corrode very slowly.
Prevention From Corrosion
Corrosion causes great damages to metallic articles such as bridges, ships and vehicles. It has been found out that due to corrosion, one fifth of iron is lost annually. Therefore, any one of the following methods are adopted to prevent corrosion.
1. Protective Metallic Coating
In this method, the metal is coated with a thin layer of less oxidizing metal, which reduces the rate of corrosion. For example, corrosion of iron is prevented by coating it with zinc, tin or chromium.
2. Non-Metallic Material Coating
In this method, the metal is coated with a thin layer of non metallic material such as paints, oils, grease, plastic emulsion, enamels etc. For example, red lead (Pb3O4) and zinc chromate (ZnCrO4) are often used for this purpose.
3. Alloying of Metals
Metals can be made more reistant against corrosion by making their alloys. For example, stainless steal is an alloy of Fe, Cr and Ni.
4. Electro-Plating
Noble and bare metals are used for Electro-Plating on any desired metal.
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Bleaching Powder (Short Note)
Definition
Bleaching powder is a white amorphous powder with smell of chlorine.
Formula of Bleaching Powder
On the basis of available percentage of chlorine, the formula of bleaching powder was suggested by Professor Odling. The formula is given by
Ca(OCl)Cl or CaOCl2
Preparation of Bleaching Powder
Bleaching powder is prepared on the large scale by Hasen Clever Process. The plant consist of a number of iron cylinders in which chlorine is brought in contact with slaked lime [Ca (OH)2].
Ca(OH)2 + Cl2 ----> CaOCl2 + H2O
Chemical Reactions of Bleaching Powder
1. In aqueous solution bleaching powder liberates chlorine.
CaOCl2 + H2O ----> Ca(OH)2 + Cl2
2. It reacts with acids to set free chlorine.
CaOCl2 + 2HCl ----> CaCl2 + H2O + Cl2
3. It reacts with atmospheric CO2 and moisture to give following reaction.
2CaOCl2 + CO2 + H2O ----> CaCO3 + CaCl2 + 2HOCl
Uses of Bleaching Powder
1. It is used for sterilization of drinking water.
2. It is used for bleaching of cotton, linen and paper pulp.
3. It is used for the preparation of Cl2 gas and chloroform (CHCl3)
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Definition
Bleaching powder is a white amorphous powder with smell of chlorine.
Formula of Bleaching Powder
On the basis of available percentage of chlorine, the formula of bleaching powder was suggested by Professor Odling. The formula is given by
Ca(OCl)Cl or CaOCl2
Preparation of Bleaching Powder
Bleaching powder is prepared on the large scale by Hasen Clever Process. The plant consist of a number of iron cylinders in which chlorine is brought in contact with slaked lime [Ca (OH)2].
Ca(OH)2 + Cl2 ----> CaOCl2 + H2O
Chemical Reactions of Bleaching Powder
1. In aqueous solution bleaching powder liberates chlorine.
CaOCl2 + H2O ----> Ca(OH)2 + Cl2
2. It reacts with acids to set free chlorine.
CaOCl2 + 2HCl ----> CaCl2 + H2O + Cl2
3. It reacts with atmospheric CO2 and moisture to give following reaction.
2CaOCl2 + CO2 + H2O ----> CaCO3 + CaCl2 + 2HOCl
Uses of Bleaching Powder
1. It is used for sterilization of drinking water.
2. It is used for bleaching of cotton, linen and paper pulp.
3. It is used for the preparation of Cl2 gas and chloroform (CHCl3)
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Silvering Of Mirror (Short Note)
Mirror
A mirror is a glass plate coated with silver film on one side.
Silvering of Mirror
Coating a glass plate with silver is called silvering of mirror.
Explanation
When ammonical silver nitrate solution is treated with an aldehyde or other organic reducing agent on the surface of a glass plate the silver (I) is reduced to silver (0). This metallic silver is deposited on the glass plate as a fine film.
The chemical reactions that occur are as follows.
AgNO3 + 2NH4OH ----> [Ag(NH3)2]+ + NO3- + 2H2O
[Ag(NH3)2]+ + RCHO + H2O ----> Ag0↓ + RCOOH + 2NH4+
Method
The process of silvering of mirror is carried out through the following steps.
1. A solution of silver nitrate and ammonia is prepared in distilled water.
2. The aqueous solution of ammonia is slowly added to the solution of silver nitrate until brown precipitates of silver oxide form and dissolve.
3. The mixture is ammonical silver nitrate solution. This solution is mixed with a solution of an organic reducing agent such as glucose.
4. After mixing all the compounds thoroughly, the solution is poured on to the centre of a clean glass surface.
5. The reaction immediately starts and thin film metallic silver deposited on the surface of the glass.
6. The silver film is then coated with either shellae of copal varnish. Finally it is painted with some colour, normally red.
Spraying Method
Silvering of mirror can also be carried out by spraying method. In this technique, the mixture of chemicals is sprayed onto the glass sheet.
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Mirror
A mirror is a glass plate coated with silver film on one side.
Silvering of Mirror
Coating a glass plate with silver is called silvering of mirror.
Explanation
When ammonical silver nitrate solution is treated with an aldehyde or other organic reducing agent on the surface of a glass plate the silver (I) is reduced to silver (0). This metallic silver is deposited on the glass plate as a fine film.
The chemical reactions that occur are as follows.
AgNO3 + 2NH4OH ----> [Ag(NH3)2]+ + NO3- + 2H2O
[Ag(NH3)2]+ + RCHO + H2O ----> Ag0↓ + RCOOH + 2NH4+
Method
The process of silvering of mirror is carried out through the following steps.
1. A solution of silver nitrate and ammonia is prepared in distilled water.
2. The aqueous solution of ammonia is slowly added to the solution of silver nitrate until brown precipitates of silver oxide form and dissolve.
3. The mixture is ammonical silver nitrate solution. This solution is mixed with a solution of an organic reducing agent such as glucose.
4. After mixing all the compounds thoroughly, the solution is poured on to the centre of a clean glass surface.
5. The reaction immediately starts and thin film metallic silver deposited on the surface of the glass.
6. The silver film is then coated with either shellae of copal varnish. Finally it is painted with some colour, normally red.
Spraying Method
Silvering of mirror can also be carried out by spraying method. In this technique, the mixture of chemicals is sprayed onto the glass sheet.
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Glass (Short Note)
Definition
Glass is a hard material that is usually transparent made by cooling certain molten materials in such a manner that they do not crystallize but remain in amorphous state.
Glass is considered to be a super cooled liquid, i.e. the solid in which the molecules are present as aggregates as in liquid, and are not present in any definite pattern.
Preparation of Glass
The principle ingredients of all types of glass are sand or silica (SiO2). Therefore, glass is one of the most important artificial silicates. For example, the ordinary soft glass or Soda Glass is a mixture of Sodium Silicate (Na2SiO3) and Calsium Silicate (CaSiO3).
Soda glass is manufactured by heating sand (SiO2), sodium carbonate (Na2CO3) and calsium carbonate (CaCO3) in a furnace at high temperature, i.e. 1400ºC
Types of Glass
Glass is classified in a number of ways on the basis of its chemical composition, properties, manufacturing process or it's use. Some important types of glass are as follows.
1. Soft Glass or Soda Glass
Soft glass or Soda glass is an ordinary glass which is a mixture of sodium silicate and sodium calcium silicate. it is also known as window glass.
2. Refractory Potassium Glass
It is a mixture of potassium silicate and calcium silicate. It has high refractive index. This glass is used for making prism, lenses and decorative glass wear.
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3. Pyrex Glass
It is boro silicated glass. The main constituents of Pyrex Glass are boroxide (B2O3) and silica (SiO2). This glass has no chemical durability and is soluble even in water.
4. Water Glass
Water glass is just a sodium silicate, which is prepared by the reaction of sodium oxide (Na2O) and silica (SiO2). This glass has no chemical durability and is soluble even in water.
5. Coloured Glass
Coloured glass is prepared by adding certain transition metal oxides. For example copper oxide (CuO) gives light blue coloured glass, where as cobalt oxide (CoO) gives dark blue colour, chromium oxide (Cr2O3) gives green colour and zinc oxide (ZnO) give red coloured glass.
6. Photochromic Glass or Photosensitive Glass
Photochromic glass produces darkness on exposure to bright sunlight but becomes clear again in absence of light. This glass contains silver chloride or silver bromide salts which is sensitive to light, in presence of light, the salt is decomposed to give finely divided black silver, in absence of sunlight, silver and chloride recombine to reform AgCl. This glass is used in sunglasses.
7. Optical Fibres
Optical fibres are thin fibres of silica glass of high purity. They have excellent optical transparency. This glass is used to transmit T.V Programs, Telephone conversion, Computer output etc. It is also used to make a design on glass. This process is called Etching
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Definition
Glass is a hard material that is usually transparent made by cooling certain molten materials in such a manner that they do not crystallize but remain in amorphous state.
Glass is considered to be a super cooled liquid, i.e. the solid in which the molecules are present as aggregates as in liquid, and are not present in any definite pattern.
Preparation of Glass
The principle ingredients of all types of glass are sand or silica (SiO2). Therefore, glass is one of the most important artificial silicates. For example, the ordinary soft glass or Soda Glass is a mixture of Sodium Silicate (Na2SiO3) and Calsium Silicate (CaSiO3).
Soda glass is manufactured by heating sand (SiO2), sodium carbonate (Na2CO3) and calsium carbonate (CaCO3) in a furnace at high temperature, i.e. 1400ºC
Types of Glass
Glass is classified in a number of ways on the basis of its chemical composition, properties, manufacturing process or it's use. Some important types of glass are as follows.
1. Soft Glass or Soda Glass
Soft glass or Soda glass is an ordinary glass which is a mixture of sodium silicate and sodium calcium silicate. it is also known as window glass.
2. Refractory Potassium Glass
It is a mixture of potassium silicate and calcium silicate. It has high refractive index. This glass is used for making prism, lenses and decorative glass wear.
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3. Pyrex Glass
It is boro silicated glass. The main constituents of Pyrex Glass are boroxide (B2O3) and silica (SiO2). This glass has no chemical durability and is soluble even in water.
4. Water Glass
Water glass is just a sodium silicate, which is prepared by the reaction of sodium oxide (Na2O) and silica (SiO2). This glass has no chemical durability and is soluble even in water.
5. Coloured Glass
Coloured glass is prepared by adding certain transition metal oxides. For example copper oxide (CuO) gives light blue coloured glass, where as cobalt oxide (CoO) gives dark blue colour, chromium oxide (Cr2O3) gives green colour and zinc oxide (ZnO) give red coloured glass.
6. Photochromic Glass or Photosensitive Glass
Photochromic glass produces darkness on exposure to bright sunlight but becomes clear again in absence of light. This glass contains silver chloride or silver bromide salts which is sensitive to light, in presence of light, the salt is decomposed to give finely divided black silver, in absence of sunlight, silver and chloride recombine to reform AgCl. This glass is used in sunglasses.
7. Optical Fibres
Optical fibres are thin fibres of silica glass of high purity. They have excellent optical transparency. This glass is used to transmit T.V Programs, Telephone conversion, Computer output etc. It is also used to make a design on glass. This process is called Etching
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Plastic (Short Note)
Definition
Plastics are macromolecules, which are formed by the polymerization of simple molecules.
Explanation
In other words we can say that plastic are the polymers formed from monomers. The phenomenon in which simple and smaller molecules are combined together to form complex and large molecules, is called polymerization. The simple and smaller molecules are called monomers and the large and complex molecules are called polymers.
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Types of Plastic
There are the following two types of plastics.
1. Thermo Plastic
2. Thermosetting Plastic
1. Thermo Plastic
Thermo plastic is also known as Thermo-softening plastic. This type of plastic is manufactured by heating, softening melding and cooling the raw materials, this process can be repeated and it does not effect the properties of plastic.
2. Thermosetting Plastic
Thermosetting plastics are those materials, which cannot be heated, only once before they set, i.e. they cannot be reworked.
Examples of Plastic
1. Polyethene (Polythene)
In presence of traces of oxygen, when ethene is heated at 200ºC, under 100 atm pressure then polymerization takes place. As a result, polyethene is formed, which is commonly known as polythene.
Diagram Coming Soon </centre>
Uses
Polythene is the most common plastic used to form polythene bags and to package food.
2. Poly Vinyl Chloride (PVC)
PVC or Poly Vinyl Chloride is the polymer of vinyl chloride. When vinyl chloride is heated at 80ºC in the presence of catalyst hydrogen peroxide, then polymerization takes place. As a result, Poly Vinyl Chloride is formed.
Uses
PVC is used for insulating covering for electrical cables, for the manufacture of gramophone, records, suitcase covering etc.
3. Poly Vinyl Acetate (PVA)
Poly Vinyl Acetate (PVA) is the polymer of vinyl acetate.
Uses
PVA is used in the manufacture of chewing gums and in the water proofing of textiles.
4. Bakelite
Bakelite is a polymer of phenol and formaldehyde. By the condensation of two molecules of phenol with formaldehyde, a polymer Bakelite is obtained.
<center> Diagram Coming Soon
Uses
Bakelite is used to make buttons, switches, electrical boards, camera, radio, telephone etc.
Quality of Plastics
During the polymerization, some other components are also mixed to improve the quality of the plastic. For example, plasticizer is mixed with the polymer. It reduces the brittleness and improves the elasticity of plastic. Fillers are also mixed with the polymer, which usually increases the mechanical strength of plastics, Some pigments or dyes are added to get various coloured plastics.
Plastic Industry of Pakistan
The plastic industry in Pakistan essentially consists of moulding of plastic powders into various articles of daily use
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Definition
Plastics are macromolecules, which are formed by the polymerization of simple molecules.
Explanation
In other words we can say that plastic are the polymers formed from monomers. The phenomenon in which simple and smaller molecules are combined together to form complex and large molecules, is called polymerization. The simple and smaller molecules are called monomers and the large and complex molecules are called polymers.
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Types of Plastic
There are the following two types of plastics.
1. Thermo Plastic
2. Thermosetting Plastic
1. Thermo Plastic
Thermo plastic is also known as Thermo-softening plastic. This type of plastic is manufactured by heating, softening melding and cooling the raw materials, this process can be repeated and it does not effect the properties of plastic.
2. Thermosetting Plastic
Thermosetting plastics are those materials, which cannot be heated, only once before they set, i.e. they cannot be reworked.
Examples of Plastic
1. Polyethene (Polythene)
In presence of traces of oxygen, when ethene is heated at 200ºC, under 100 atm pressure then polymerization takes place. As a result, polyethene is formed, which is commonly known as polythene.
Diagram Coming Soon </centre>
Uses
Polythene is the most common plastic used to form polythene bags and to package food.
2. Poly Vinyl Chloride (PVC)
PVC or Poly Vinyl Chloride is the polymer of vinyl chloride. When vinyl chloride is heated at 80ºC in the presence of catalyst hydrogen peroxide, then polymerization takes place. As a result, Poly Vinyl Chloride is formed.
Uses
PVC is used for insulating covering for electrical cables, for the manufacture of gramophone, records, suitcase covering etc.
3. Poly Vinyl Acetate (PVA)
Poly Vinyl Acetate (PVA) is the polymer of vinyl acetate.
Uses
PVA is used in the manufacture of chewing gums and in the water proofing of textiles.
4. Bakelite
Bakelite is a polymer of phenol and formaldehyde. By the condensation of two molecules of phenol with formaldehyde, a polymer Bakelite is obtained.
<center> Diagram Coming Soon
Uses
Bakelite is used to make buttons, switches, electrical boards, camera, radio, telephone etc.
Quality of Plastics
During the polymerization, some other components are also mixed to improve the quality of the plastic. For example, plasticizer is mixed with the polymer. It reduces the brittleness and improves the elasticity of plastic. Fillers are also mixed with the polymer, which usually increases the mechanical strength of plastics, Some pigments or dyes are added to get various coloured plastics.
Plastic Industry of Pakistan
The plastic industry in Pakistan essentially consists of moulding of plastic powders into various articles of daily use
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Fertilizers (Short Note)
Definition
Fertilizers are the water soluble substances which provide one or nutrient materials to the soil essential for the nourishment of plants.
Explanation
Fertilizers are water-soluble salts that are absorbed by the plants through osmosis process. Fertilizers are mostly inorganic salts containing nitrogen phosphorus or potassium etc. these elements are essential for the growth and development of plants. Those nutrient materials which plant needs in large quantities are called Macro Nutrients. Those nutrient elements which plant need in small quantities are called Micro Nutrients.
Functions of Fertilizers
The main functions of fertilizers are
1. It helps the soil to make up the deficiency of nutrient element and becomes fertile again.
2. The main function of fertilizers is to maintain the pH of soil to neutrality (7 - 8) or slightly alkalinity (10).
Types of Fertilizers
Fertilizers have been classified into the following types.
1. Natural Fertilizers
2. Artificial Fertilizers
1. Natural Fertilizers
Natural Fertilizers are also known as organic fertilizers. The main source of natural fertilizers is the excretory product of animals and decade product of plants.
2. Artificial Fertilizers
Artificial Fertilizers are also known as synthetic fertilizers and mineral fertilizers. They are obtained from raw mineral materials.
Artificial fertilizers have been further classified into
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a. Nitrogenous Fertilizer
In these fertilizers, nitrogen is present as the essential element.
Example
Ammonium Nitrate - NH4NO3
Ammonium Sulphate - (NH4)2SO4
b. Potassic Fertilizer
In these fertilizers, Potassium is present as the essential element.
Example
Chilli Salt Peter - KNO3
c. Phosphatic Fertilizer
In these fertilizers, phosphate is present as the essential element. Phosphatic fertilizers are further classified into following.
i. Super Phosphate
The raw material of super phosphate fertilizer is phosphorite. The molecular formula of Phosphorite is [Ca3(PO4)2]3 CaF2. This rock reacts with sulphuric acid and converts into water soluble super phosphate.
Ca3(PO4)2 + 2H2SO4 ----> Ca(H2PO4)2 + 2CaSO4
The mixture of calsium dihydrogen phosphate and gypsum is called super phosphate.
ii. Triple Phosphate
This phosphate fertilizer is obtained by the decomposition of phosphate rock or phosphorite with phosphoric acid.
Ca3(PO4)2 + 4H3PO4 ----> 3Ca(H2PO4)2
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Definition
Fertilizers are the water soluble substances which provide one or nutrient materials to the soil essential for the nourishment of plants.
Explanation
Fertilizers are water-soluble salts that are absorbed by the plants through osmosis process. Fertilizers are mostly inorganic salts containing nitrogen phosphorus or potassium etc. these elements are essential for the growth and development of plants. Those nutrient materials which plant needs in large quantities are called Macro Nutrients. Those nutrient elements which plant need in small quantities are called Micro Nutrients.
Functions of Fertilizers
The main functions of fertilizers are
1. It helps the soil to make up the deficiency of nutrient element and becomes fertile again.
2. The main function of fertilizers is to maintain the pH of soil to neutrality (7 - 8) or slightly alkalinity (10).
Types of Fertilizers
Fertilizers have been classified into the following types.
1. Natural Fertilizers
2. Artificial Fertilizers
1. Natural Fertilizers
Natural Fertilizers are also known as organic fertilizers. The main source of natural fertilizers is the excretory product of animals and decade product of plants.
2. Artificial Fertilizers
Artificial Fertilizers are also known as synthetic fertilizers and mineral fertilizers. They are obtained from raw mineral materials.
Artificial fertilizers have been further classified into
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a. Nitrogenous Fertilizer
In these fertilizers, nitrogen is present as the essential element.
Example
Ammonium Nitrate - NH4NO3
Ammonium Sulphate - (NH4)2SO4
b. Potassic Fertilizer
In these fertilizers, Potassium is present as the essential element.
Example
Chilli Salt Peter - KNO3
c. Phosphatic Fertilizer
In these fertilizers, phosphate is present as the essential element. Phosphatic fertilizers are further classified into following.
i. Super Phosphate
The raw material of super phosphate fertilizer is phosphorite. The molecular formula of Phosphorite is [Ca3(PO4)2]3 CaF2. This rock reacts with sulphuric acid and converts into water soluble super phosphate.
Ca3(PO4)2 + 2H2SO4 ----> Ca(H2PO4)2 + 2CaSO4
The mixture of calsium dihydrogen phosphate and gypsum is called super phosphate.
ii. Triple Phosphate
This phosphate fertilizer is obtained by the decomposition of phosphate rock or phosphorite with phosphoric acid.
Ca3(PO4)2 + 4H3PO4 ----> 3Ca(H2PO4)2
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Varnish (Short Note)
Varnish is a mixture of resin, volatile organic solvents and drying oils. To prepare Varnish such as resin (plastic in liquid state) is dissolved in volatile organic solvents, such as ether or alcohol and then drying oil such as linseed oil is added to it.
The drying oils such as linseed oil consist of esters of highly unsaturated acids containing two or more double bonds. When exposed to air, these oils absorb oxygen and form hard and tough film. The film is insoluble in water.
When a Varnish is applied to the surface, the volatile organic solvents evaporate quickly and the drying oil absorbs oxygen and a hard tough glossy film is obtained. The glossy appearance of the film is due to the presence of resin. Varnish differ from paints in such a manner that, it does not has any added pigment.
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Varnish is a mixture of resin, volatile organic solvents and drying oils. To prepare Varnish such as resin (plastic in liquid state) is dissolved in volatile organic solvents, such as ether or alcohol and then drying oil such as linseed oil is added to it.
The drying oils such as linseed oil consist of esters of highly unsaturated acids containing two or more double bonds. When exposed to air, these oils absorb oxygen and form hard and tough film. The film is insoluble in water.
When a Varnish is applied to the surface, the volatile organic solvents evaporate quickly and the drying oil absorbs oxygen and a hard tough glossy film is obtained. The glossy appearance of the film is due to the presence of resin. Varnish differ from paints in such a manner that, it does not has any added pigment.
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Paints (Short Note)
Definition
Paints are fluids that are applied on a surface to form a hard continuous film on it for protection or decoration.
Wooden and metallic articles are coated with paints to decorate them as well as to protect from corrosion or rusting.
Composition of Paints
Paints are usually composed of three components.
1. Pigments
2. Binders
3. Volatile Solvent
To make a paint, a suitable solvent is used in which both the binder and the pigment are dissolved.
1. Pigments
The pigment of paint gives it colour, it also gives hardness and bulk. Common pigments are titanium dioxide - TiO2 (white), Iron oxide - Fe2O3 (brown or red), Carbon Black - C (black), Chrome Yellow - PbCrO4 (yellow) and organic dyes of various colours.
2. Binders
The binder or vehicle is the part of the paint that carries the pigment particles and hold the entire film of the paint on the surface. Generally some plant oils such as linseed oil, natural and synthetic resin (liquid plastics) are used as binders.
3. Volatile Solvents
To make paint a suitable solvent is selected in which both the pigment and binder are dissolved. The solvent evaporates after the paint is applied. Solvent does not effect the quality of dry paint. Commonly, water or turpentine is used as solvent.
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Classification of Paints
On the basis of nature of solvent, the paints are classified into the following two classes.
1. Oil Based Paints
2. Water Based Paints
1. Oil Based Paints
In these paints turpentine is used as solvent. Turpentine is a liquid mixture of hydrocarbon that is obtained from pine trees.
2. Water Based Paints
In these paints, water is used as solvent. Both binders and pigments form a suspension in water
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Definition
Paints are fluids that are applied on a surface to form a hard continuous film on it for protection or decoration.
Wooden and metallic articles are coated with paints to decorate them as well as to protect from corrosion or rusting.
Composition of Paints
Paints are usually composed of three components.
1. Pigments
2. Binders
3. Volatile Solvent
To make a paint, a suitable solvent is used in which both the binder and the pigment are dissolved.
1. Pigments
The pigment of paint gives it colour, it also gives hardness and bulk. Common pigments are titanium dioxide - TiO2 (white), Iron oxide - Fe2O3 (brown or red), Carbon Black - C (black), Chrome Yellow - PbCrO4 (yellow) and organic dyes of various colours.
2. Binders
The binder or vehicle is the part of the paint that carries the pigment particles and hold the entire film of the paint on the surface. Generally some plant oils such as linseed oil, natural and synthetic resin (liquid plastics) are used as binders.
3. Volatile Solvents
To make paint a suitable solvent is selected in which both the pigment and binder are dissolved. The solvent evaporates after the paint is applied. Solvent does not effect the quality of dry paint. Commonly, water or turpentine is used as solvent.
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Classification of Paints
On the basis of nature of solvent, the paints are classified into the following two classes.
1. Oil Based Paints
2. Water Based Paints
1. Oil Based Paints
In these paints turpentine is used as solvent. Turpentine is a liquid mixture of hydrocarbon that is obtained from pine trees.
2. Water Based Paints
In these paints, water is used as solvent. Both binders and pigments form a suspension in water
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Isomerism (Short Note)
Definition
The phenomenon in which different compounds have the same molecular formula but different structural formula or electronic configuration is known as Isomerism.
The different compounds are called Isomers.
Types of Isomerism
There are various types of isomerism, but the four important types are
1. Chain Isomerism
2. Position Isomerism
3. Functional group Isomerism
4. Metamerism
1 Chain Isomerism
The phenomenon in which different compounds have the same molecular formula but differ in length of carbon chain is called Chain Isomerism. The structures are known as Chain Isomers.
Examples
1. Methane, Ethane and Propane have no chain isomers because the cannot be rearranged with small carbon chain.
CH4 CH3-CH3 CH3-CH2-CH3
2. The carbon chain of butane (C4H10) is long enough. So, butane has two isomers.
CH3-CH2-CH2-CH3 (n-butane)
CH3-CHCH3-CH3 (iso-butane)
3. Pentane (C5H12) shows the following isomers.
CH3-CH2-CH2-CH2-CH3 (N-PENTANE)
CH3-CHCH3-CH2-CH3 (ISO-PENTANE)
In saturated hydrocarbons, the number of isomers increase with increase in number of carbon atoms. This is the reason why decane shows 75 isomers.
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2. Position Isomerism
The phenomenon in which different compounds have same molecular formula but differ in position of functional group, double bond or triple bond in same length of carbon chain is called Position Isomerism. The structures are called Position Isomers.
Examples
1. Propyl alcohol shows two position isomers.
Diagram Coming Soon
2. Butene C4H8 has two position isomers.
Diagram Coming Soon
3. Functional Group Isomerism
The phenomenon in which different compounds have same molecular formula but differ in functional groups is called functional group Isomerism. The structures are known as functional group isomers.
4. Metamerism
The phenomenon in which different compounds have same molecular formula and functional group but different alkyl groups attached to the same multivalent atom is called metamerism
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Definition
The phenomenon in which different compounds have the same molecular formula but different structural formula or electronic configuration is known as Isomerism.
The different compounds are called Isomers.
Types of Isomerism
There are various types of isomerism, but the four important types are
1. Chain Isomerism
2. Position Isomerism
3. Functional group Isomerism
4. Metamerism
1 Chain Isomerism
The phenomenon in which different compounds have the same molecular formula but differ in length of carbon chain is called Chain Isomerism. The structures are known as Chain Isomers.
Examples
1. Methane, Ethane and Propane have no chain isomers because the cannot be rearranged with small carbon chain.
CH4 CH3-CH3 CH3-CH2-CH3
2. The carbon chain of butane (C4H10) is long enough. So, butane has two isomers.
CH3-CH2-CH2-CH3 (n-butane)
CH3-CHCH3-CH3 (iso-butane)
3. Pentane (C5H12) shows the following isomers.
CH3-CH2-CH2-CH2-CH3 (N-PENTANE)
CH3-CHCH3-CH2-CH3 (ISO-PENTANE)
In saturated hydrocarbons, the number of isomers increase with increase in number of carbon atoms. This is the reason why decane shows 75 isomers.
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2. Position Isomerism
The phenomenon in which different compounds have same molecular formula but differ in position of functional group, double bond or triple bond in same length of carbon chain is called Position Isomerism. The structures are called Position Isomers.
Examples
1. Propyl alcohol shows two position isomers.
Diagram Coming Soon
2. Butene C4H8 has two position isomers.
Diagram Coming Soon
3. Functional Group Isomerism
The phenomenon in which different compounds have same molecular formula but differ in functional groups is called functional group Isomerism. The structures are known as functional group isomers.
4. Metamerism
The phenomenon in which different compounds have same molecular formula and functional group but different alkyl groups attached to the same multivalent atom is called metamerism
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Detergent (Short Note)
Definition
Detergents are the salts of alkyl sulphate or aryl sulphate that improves the cleaning action of solvents, particularly ionic solvents.
Explaination
Detergents are long chain molecules, which when dissolve in water dissociate into positive and negative ions, these ions react with the ions of dirt and grease to produce soluble compounds with are readily carried away by the water molecules.
General Formula
Detergents are sodium or potassium salts of alkyl sulphate or aryl sulphate.
R-OSO3-Na+ Sodium Alkyl Sulphate
Where R is an alkyl group containing 7 to 18 carbon atoms. Soaps are sodium or potassium salts of long chain fatty acids.
R - COO-Na+
Composition of Detergents
Detergents are composed of two main parts namely.
1. Hydrophobic Part
2. Hydrophilic Part
1. Hydrophobic Part
It is a water repelling part of detergent, which consist of long hydrocarbon chain. The hydrocarbon chain being non-polar attracts dirt particles, which are normally non polar, i.e. greasy or oily molecules. Therefore, this part of detergent removes dirt particles from thing being washed and water takes away the dirt particles with it.
2. Hydrophilic Part
Hydrophilic part of the detergent is water attracting part. It consists of small ionic groups such as sulphonate (SO3) and sulphate (-SO3-). The hydrophilic group being ionic gets attracted by the polar water molecules and in this way, this part of the detergent removes the ionic dirt particles.
Advantage of Detergents
Detergents can act in hard water, since the calsium and magnesium salts of detergents are soluble in water. Whereas, the corresponding salts of soap are insoluble in water. Thus detergents are better cleaning agents than soaps.
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Disadvantages of Detergents
One disadvantage of detergent over soap is that hydrocarbon chain, unlike those of soaps, which are derived from food substances (fats and oil) cannot be broken down by bacteria and dispersads. Therefore, it causes water pollution
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Definition
Detergents are the salts of alkyl sulphate or aryl sulphate that improves the cleaning action of solvents, particularly ionic solvents.
Explaination
Detergents are long chain molecules, which when dissolve in water dissociate into positive and negative ions, these ions react with the ions of dirt and grease to produce soluble compounds with are readily carried away by the water molecules.
General Formula
Detergents are sodium or potassium salts of alkyl sulphate or aryl sulphate.
R-OSO3-Na+ Sodium Alkyl Sulphate
Where R is an alkyl group containing 7 to 18 carbon atoms. Soaps are sodium or potassium salts of long chain fatty acids.
R - COO-Na+
Composition of Detergents
Detergents are composed of two main parts namely.
1. Hydrophobic Part
2. Hydrophilic Part
1. Hydrophobic Part
It is a water repelling part of detergent, which consist of long hydrocarbon chain. The hydrocarbon chain being non-polar attracts dirt particles, which are normally non polar, i.e. greasy or oily molecules. Therefore, this part of detergent removes dirt particles from thing being washed and water takes away the dirt particles with it.
2. Hydrophilic Part
Hydrophilic part of the detergent is water attracting part. It consists of small ionic groups such as sulphonate (SO3) and sulphate (-SO3-). The hydrophilic group being ionic gets attracted by the polar water molecules and in this way, this part of the detergent removes the ionic dirt particles.
Advantage of Detergents
Detergents can act in hard water, since the calsium and magnesium salts of detergents are soluble in water. Whereas, the corresponding salts of soap are insoluble in water. Thus detergents are better cleaning agents than soaps.
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Disadvantages of Detergents
One disadvantage of detergent over soap is that hydrocarbon chain, unlike those of soaps, which are derived from food substances (fats and oil) cannot be broken down by bacteria and dispersads. Therefore, it causes water pollution
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Cracking Or Pyrolysis (Short Note)
Definition
The phenomenon in which large molecules of hydrocarbons are thermally decomposed into smaller molecules in the absence of air or oxygen is known as Cracking or Pyrolysis.
Examples of Cracking
Cracking can be explained with the help of following examples.
1. Methane
When methane is burnt in absence of air then cracking takes place, as a result carbon black and hydrogen are formed.
2. Gasoline
The most important fraction of petroleum is gasoline (petrol) which is used as motor fuel. The fractional distillation of petroleum yields only a small percentage of total petrol demand. The additional quantity of petrol is obtained by the cracking of diesel.
The large less volatile molecules of diesel that have high boiling point are heated in the absence of air using a catalyst. As a result, cracking takes place and smaller more volatile molecules of petrol having lower boiling point are obtained.
Thus cracking is applied to obtain additional amount of gasoline from crude oil. In cracking a number of other useful by products are also obtained
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Definition
The phenomenon in which large molecules of hydrocarbons are thermally decomposed into smaller molecules in the absence of air or oxygen is known as Cracking or Pyrolysis.
Examples of Cracking
Cracking can be explained with the help of following examples.
1. Methane
When methane is burnt in absence of air then cracking takes place, as a result carbon black and hydrogen are formed.
2. Gasoline
The most important fraction of petroleum is gasoline (petrol) which is used as motor fuel. The fractional distillation of petroleum yields only a small percentage of total petrol demand. The additional quantity of petrol is obtained by the cracking of diesel.
The large less volatile molecules of diesel that have high boiling point are heated in the absence of air using a catalyst. As a result, cracking takes place and smaller more volatile molecules of petrol having lower boiling point are obtained.
Thus cracking is applied to obtain additional amount of gasoline from crude oil. In cracking a number of other useful by products are also obtained
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Polymerization (Short Note)
Definition
The phenomenon in which simple and small molecules are converted into large and complex molecules is known as Polymerization.
The simple and small molecules are known as monomer, where as large and complex molecules are called polymers.
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Classification of Polymerization
Polymerization has been classified the following.
1. Addition Polymerization
2. Condensation Polymerization
1. Addition Polymerization
The process of Polymerization in which molecules are added into each other is called Addition Polymerization.
Examples
In presence of traces of oxygen when is heated at about 200ºC under 100 atm pressure, then Polymerization takes place. As a result, monomers add together to form polymer i.e. Polyethene or Polythene.
Diagram Coming Soon Similarly the Polymerization of Vinyl Chloride to Poly Vinyl Chloride (PVC) and Polymerization of Vinyl Acetate to Poly Vinyl Acetate (PVA) are the examples of Addition Polymerization.
2. Condensation Polymerization
The process of Polymerization in which removal of water molecule takes place with the formation of polymer is called Condensation Polymerization.
Example
Bakelite Plastic is the Polymer that is obtained by the polymerization of Phenol and formaldehyde. During this process removal of water molecule takes place
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Definition
The phenomenon in which simple and small molecules are converted into large and complex molecules is known as Polymerization.
The simple and small molecules are known as monomer, where as large and complex molecules are called polymers.
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Classification of Polymerization
Polymerization has been classified the following.
1. Addition Polymerization
2. Condensation Polymerization
1. Addition Polymerization
The process of Polymerization in which molecules are added into each other is called Addition Polymerization.
Examples
In presence of traces of oxygen when is heated at about 200ºC under 100 atm pressure, then Polymerization takes place. As a result, monomers add together to form polymer i.e. Polyethene or Polythene.
Diagram Coming Soon Similarly the Polymerization of Vinyl Chloride to Poly Vinyl Chloride (PVC) and Polymerization of Vinyl Acetate to Poly Vinyl Acetate (PVA) are the examples of Addition Polymerization.
2. Condensation Polymerization
The process of Polymerization in which removal of water molecule takes place with the formation of polymer is called Condensation Polymerization.
Example
Bakelite Plastic is the Polymer that is obtained by the polymerization of Phenol and formaldehyde. During this process removal of water molecule takes place
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Phenol
Definition
Aeromatic alcohols are called Phenols.
OR
Those derivations of benzene in which hydrogen atom is replaced by OH group are known as Phenol.
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Classification of Phenol
On the basis of hydroxyl group (OH) bonded with benzene ring, Phenol are classified into following three classes.
1. Mono Hydric Phenol
2. Di Hydric Phenol
3. Tri Hydric Phenol
1. Mono Hydric Phenol
Those aeromatic phenols which contains only one OH group are called Mono Hydric Phenol.
2. Di Hydric Phenol
Those aeromatic phenols which contain two OH groups are called Di Hydric Phenol.
Diagram Coming Soon
3. Tri Hydric Phenol
Those aeromatic phenols which contain three OH groups are called Tri Hydric Alcohols.
Preparation
Phenol can be prepared by following methods.
1. From Chloro Benzene (Down's Process)
When chloro benzene is heated with 10% NaOH solution at 300ºC under 200 atm pressure then sodium Phenoxide is formed, which on further heating with HCl convert into Phenol.
Diagram Coming Soon
2. From Benzene Sulphonate
When benzene sulphonate is fused with NaOH at 25ºC ten sodium Phenoxide is formed, which on further heating with HCl convert into Phenol.
Diagram Coming Soon
Physical Properties
1. At ordinary temperature and pressure, phenol exist as colourless, crystalline solid.
2. Phenol has peculiar smell.
3. Phenol is a poisonous compound.
4. The melting point of phenol is 43ºC and its boiling point is 182ºC.
5. Above 68.5ºC Phenol is completely soluble in water.
Chemical Properties
The important chemical reactions of Phenol are
1. Reaction with Sodium Hydroxide (NaOH)
When phenol reacts with NaOH then sodium Phenoxide and water are formed. This reactions shows the acidic nature of phenol.
Diagram Coming Soon
2. Reaction with Zinc Dust
When vapours of phenol are passed through red hot zinc dust then benzene is formed.
Diagram Coming Soon
3. Hydrogenation
Introduction of hydrogen in a compound is called Hydrogenation. In presence of catalyst nickle when phenol is heated with hydrogen at about 150ºC then hydrogenation takes place as a result cyclo hexanol is formed.
Diagram Coming Soon
4. Reaction with Bromine Water
In presence of water, when bromine reacts with phenol then 2, 4, 6 - tri bromo phenol is formed.
Diagram Coming Soon
5. Reaction with Concentrated Nitic Acid
When phenol reacts with concentrated nitric acid then 2, 4, 6 - tri phenol (Picric Acid) is formed.
Diagram Coming Soon
6. Reaction with Dilute Nitric Acid
When Phenol react with dilute nitric acid then a mixture of ortho and Para nitro Phenol is formed.
Diagram Coming Soon
7. Reaction with Sulphuric Acid
When phenol reacts with H2SO4 then ortho phenol sulphonic acid and para phenol sulphonic acid are formed. The amount of product depending upon the temperature, lower pressure i.e. (15 - 20ºC) favours the production of ortho phenol sulphonic acid where as high temperature about 100ºC favours the production of para phenol sulphonic acid.
Diagram Coming Soon
Uses
1. Phenol is uses as antiseptic.
2. Phenol is used in the manufacture of soaps, plastics etc.
3. Phenol is used in the preparation of Picric Acid and Aspirin.
4. It is used as link Preservative
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Definition
Aeromatic alcohols are called Phenols.
OR
Those derivations of benzene in which hydrogen atom is replaced by OH group are known as Phenol.
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Classification of Phenol
On the basis of hydroxyl group (OH) bonded with benzene ring, Phenol are classified into following three classes.
1. Mono Hydric Phenol
2. Di Hydric Phenol
3. Tri Hydric Phenol
1. Mono Hydric Phenol
Those aeromatic phenols which contains only one OH group are called Mono Hydric Phenol.
2. Di Hydric Phenol
Those aeromatic phenols which contain two OH groups are called Di Hydric Phenol.
Diagram Coming Soon
3. Tri Hydric Phenol
Those aeromatic phenols which contain three OH groups are called Tri Hydric Alcohols.
Preparation
Phenol can be prepared by following methods.
1. From Chloro Benzene (Down's Process)
When chloro benzene is heated with 10% NaOH solution at 300ºC under 200 atm pressure then sodium Phenoxide is formed, which on further heating with HCl convert into Phenol.
Diagram Coming Soon
2. From Benzene Sulphonate
When benzene sulphonate is fused with NaOH at 25ºC ten sodium Phenoxide is formed, which on further heating with HCl convert into Phenol.
Diagram Coming Soon
Physical Properties
1. At ordinary temperature and pressure, phenol exist as colourless, crystalline solid.
2. Phenol has peculiar smell.
3. Phenol is a poisonous compound.
4. The melting point of phenol is 43ºC and its boiling point is 182ºC.
5. Above 68.5ºC Phenol is completely soluble in water.
Chemical Properties
The important chemical reactions of Phenol are
1. Reaction with Sodium Hydroxide (NaOH)
When phenol reacts with NaOH then sodium Phenoxide and water are formed. This reactions shows the acidic nature of phenol.
Diagram Coming Soon
2. Reaction with Zinc Dust
When vapours of phenol are passed through red hot zinc dust then benzene is formed.
Diagram Coming Soon
3. Hydrogenation
Introduction of hydrogen in a compound is called Hydrogenation. In presence of catalyst nickle when phenol is heated with hydrogen at about 150ºC then hydrogenation takes place as a result cyclo hexanol is formed.
Diagram Coming Soon
4. Reaction with Bromine Water
In presence of water, when bromine reacts with phenol then 2, 4, 6 - tri bromo phenol is formed.
Diagram Coming Soon
5. Reaction with Concentrated Nitic Acid
When phenol reacts with concentrated nitric acid then 2, 4, 6 - tri phenol (Picric Acid) is formed.
Diagram Coming Soon
6. Reaction with Dilute Nitric Acid
When Phenol react with dilute nitric acid then a mixture of ortho and Para nitro Phenol is formed.
Diagram Coming Soon
7. Reaction with Sulphuric Acid
When phenol reacts with H2SO4 then ortho phenol sulphonic acid and para phenol sulphonic acid are formed. The amount of product depending upon the temperature, lower pressure i.e. (15 - 20ºC) favours the production of ortho phenol sulphonic acid where as high temperature about 100ºC favours the production of para phenol sulphonic acid.
Diagram Coming Soon
Uses
1. Phenol is uses as antiseptic.
2. Phenol is used in the manufacture of soaps, plastics etc.
3. Phenol is used in the preparation of Picric Acid and Aspirin.
4. It is used as link Preservative
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Ether O
Definition
Organic compounds which contain divalent functional group - O - are called ether.
General Formula
They are denoted by ROR where R may be any alkyl group. The alkyl groups of ether may be similar or different. The general formula of ether is
CnH2n+1 - O - CnH2n+1
Where n may be any natural number.
Examples
1. CH3-O-CH3 (DiMethyl Ether)
2. CH3-O-C2H5 (Ethyl Methyl Ether)
Preparation
Ether can be prepared by the following methods.
1. From Ethyl Alcohol
William son prepared diethyl ether from alcohol by using sodium metal or sulphuric acid therefore this method is also William son synthesis.
2. From Ethyl Chloride
When ethyl chloride is heated with dry silver oxide then diethyl ether is formed.
2C2H5Cl + Ag2O ----> C2H5 - O - C2H5 + AgCl
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Chemical Properties
Reactivity
Due to greater stability diethyl ether is relatively unreative. When diethyl ether reacts with strong acid such as hydrogen iodide then oxonium ion is formed, which reacts with strong nucleophile and convert into ethyl alcohol and ethyl iodide.
C2H5-O-C2H5 + HI ----> C2H5-OH-C2H5 + I
C2H5-OH-C2H5 + I ----> C2H5-OH + C2H5I
Uses of Ether
1. Ether is used as solvent.
2. It is used as general anaesthetic.
3. Ether is used in the manufacture of smokeless powder
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Definition
Organic compounds which contain divalent functional group - O - are called ether.
General Formula
They are denoted by ROR where R may be any alkyl group. The alkyl groups of ether may be similar or different. The general formula of ether is
CnH2n+1 - O - CnH2n+1
Where n may be any natural number.
Examples
1. CH3-O-CH3 (DiMethyl Ether)
2. CH3-O-C2H5 (Ethyl Methyl Ether)
Preparation
Ether can be prepared by the following methods.
1. From Ethyl Alcohol
William son prepared diethyl ether from alcohol by using sodium metal or sulphuric acid therefore this method is also William son synthesis.
2. From Ethyl Chloride
When ethyl chloride is heated with dry silver oxide then diethyl ether is formed.
2C2H5Cl + Ag2O ----> C2H5 - O - C2H5 + AgCl
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Chemical Properties
Reactivity
Due to greater stability diethyl ether is relatively unreative. When diethyl ether reacts with strong acid such as hydrogen iodide then oxonium ion is formed, which reacts with strong nucleophile and convert into ethyl alcohol and ethyl iodide.
C2H5-O-C2H5 + HI ----> C2H5-OH-C2H5 + I
C2H5-OH-C2H5 + I ----> C2H5-OH + C2H5I
Uses of Ether
1. Ether is used as solvent.
2. It is used as general anaesthetic.
3. Ether is used in the manufacture of smokeless powder
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Ester COO
Definition
Organic compounds that contain divalent functional group - COO - are called ester.
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General Formula
They are denoted by RCOOR where R may be any alkyl group. The alkyl groups of ester may be similar or different. The general formula of ester is
CnH2n+1 - COO - CnH2n+1
Where n may be any natural number.
Structure
The structural formula of ester shows that it contains a Carbonyl group.
RCOOR
Examples
1. Dimethyl Ester (CH3COOCH3)
Uses of Ester
1. It is used as a good solvent for paints, varnishes, oils, fats, gums, resins, cellulose etc.
2. It is used as plasticizer.
3. It is used in the preparation of artificial flavours and essences
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Definition
Organic compounds that contain divalent functional group - COO - are called ester.
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General Formula
They are denoted by RCOOR where R may be any alkyl group. The alkyl groups of ester may be similar or different. The general formula of ester is
CnH2n+1 - COO - CnH2n+1
Where n may be any natural number.
Structure
The structural formula of ester shows that it contains a Carbonyl group.
RCOOR
Examples
1. Dimethyl Ester (CH3COOCH3)
Uses of Ester
1. It is used as a good solvent for paints, varnishes, oils, fats, gums, resins, cellulose etc.
2. It is used as plasticizer.
3. It is used in the preparation of artificial flavours and essences
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Carboxylic Acid COOH
Definition
Organic compounds that contain monovalent functional group - COOH are called Ketones.
General Formula
They are denoted by R may be any alkyl group. The general formula for ketone is
CnH2n+1 - COOH
Where n may be any natural number.
Structure
The Structural formula of Carboxylic Acid shows that it contains a carbonyl group.
ROH-C=O
Examples
* Acetic Acid (CH3COOH)
Preparation
Carboxylic Acid can be prepared by the following methods.
1. From Grignard's Reagent
In presence of dry ether and halogen acid when Grignard's reagent with carbondioxide then Carboxylic Acid is formed.
R-Mg-X + O=C=O ----> COOR-Mg-X ----> RCOOH + MgX2
CH3-Mg-X + 0=C=0 ----> COOCH3-Mg-X ----> CH3COOH + MgX2
2. From Oxidation of Alcohol
In presence of oxidizing agent such as a mixture of K2Cr2O7 and concentrated K2SO4, when primary alcohol is oxidized then aldehyde is form, which on further oxidation convert into Carboxylic Acid.
RCH2-OH ----> RCHO ----> RCOH-O
CH3CH2-OH ----> CH3CHO ----> CH3COH=O
3. From Dehydrogenation of Alcohol
In presence of catalyst Co - Mo couple, when primary alcohol is heated at elevated temperature then aldehyde is formed, which in presence of a mixture of oxidizing agent such as K2Cr2O7 and concentrated H2SO4 convert into Carboxylic Acid.
RCH2-OH ----> RCHO ----> RCOH-O
CH3CH2-OH ----> CH3CHO ----> CH3COH=O
4. From Ethyne
This method is used for the preparation of acetaldehyde. In presence of catalyst H2SO4 and HgSO4 when ethyne reacts with water than unstable, intermediate vinyle alcohol is formed which on rearrangement of atoms convert into acetaldehyde.
H-C≡C-H + H-OH ----> C2H3OH ----> CH3-CHO ----> CH3-COOH
Uses of Carboxylic Acid
1. Carboxylic Acids are used as laboratory reagents.
2. Acetic acid is used as solvent for phosphorus, sulphur, gums and resins.
3. It is widely used in artificial leather production.
4. Acetic acid is used to prepare acetates, esters and cellulose acetate silk.
5. After colouring, it is used as vinegar.
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Definition
Organic compounds that contain monovalent functional group - COOH are called Ketones.
General Formula
They are denoted by R may be any alkyl group. The general formula for ketone is
CnH2n+1 - COOH
Where n may be any natural number.
Structure
The Structural formula of Carboxylic Acid shows that it contains a carbonyl group.
ROH-C=O
Examples
* Acetic Acid (CH3COOH)
Preparation
Carboxylic Acid can be prepared by the following methods.
1. From Grignard's Reagent
In presence of dry ether and halogen acid when Grignard's reagent with carbondioxide then Carboxylic Acid is formed.
R-Mg-X + O=C=O ----> COOR-Mg-X ----> RCOOH + MgX2
CH3-Mg-X + 0=C=0 ----> COOCH3-Mg-X ----> CH3COOH + MgX2
2. From Oxidation of Alcohol
In presence of oxidizing agent such as a mixture of K2Cr2O7 and concentrated K2SO4, when primary alcohol is oxidized then aldehyde is form, which on further oxidation convert into Carboxylic Acid.
RCH2-OH ----> RCHO ----> RCOH-O
CH3CH2-OH ----> CH3CHO ----> CH3COH=O
3. From Dehydrogenation of Alcohol
In presence of catalyst Co - Mo couple, when primary alcohol is heated at elevated temperature then aldehyde is formed, which in presence of a mixture of oxidizing agent such as K2Cr2O7 and concentrated H2SO4 convert into Carboxylic Acid.
RCH2-OH ----> RCHO ----> RCOH-O
CH3CH2-OH ----> CH3CHO ----> CH3COH=O
4. From Ethyne
This method is used for the preparation of acetaldehyde. In presence of catalyst H2SO4 and HgSO4 when ethyne reacts with water than unstable, intermediate vinyle alcohol is formed which on rearrangement of atoms convert into acetaldehyde.
H-C≡C-H + H-OH ----> C2H3OH ----> CH3-CHO ----> CH3-COOH
Uses of Carboxylic Acid
1. Carboxylic Acids are used as laboratory reagents.
2. Acetic acid is used as solvent for phosphorus, sulphur, gums and resins.
3. It is widely used in artificial leather production.
4. Acetic acid is used to prepare acetates, esters and cellulose acetate silk.
5. After colouring, it is used as vinegar.
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Aldehyde & Ketone CHO and CO
Definition of Aldehyde
Organic compounds that contain monovalent functional group - CHO are known as aldehydes.
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General Formula of Aldehyde
They are denoted by RCHO, where R may be any alkyl group. The general formula for aldehyde is
CnH2n - CHO
Where n may be any natural number.
Structure of Aldehyde
The structural formula of aldehyde shows that it contains a carbonyl group.
Examples of Aldehyde
Definition of Aldehyde
Organic compounds that contain monovalent functional group - CHO are known as aldehydes.
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General Formula of Aldehyde
They are denoted by RCHO, where R may be any alkyl group. The general formula for aldehyde is
CnH2n - CHO
Where n may be any natural number.
Structure of Aldehyde
The structural formula of aldehyde shows that it contains a carbonyl group.
Examples of Aldehyde
- CH3CHO | Acetaldehyde
- HCHO | Formaldehyde
Definition of Ketone
Organic compounds that contain divalent functional group - CO - are called Ketones.
General Formula of Ketone
They are denoted by R may be any alkyl group. The general formula for Ketone is
CnH2n+1 - CO - CnH2n+1
Where n may be any natural number.
Structure of Ketone
The structural formula of ketone shows that it contains a carbonyl group.
Example of Ketone
- CH3COCH3 (Acetone)
Preparation of Aldehyde & Ketone
Aldehyde and Ketone can be prepared by the following methods.
1. From Dehydrogenation of Alcohol
Removal of hydrogen from a compound is called dehydrogenation. In presence of catalyst, Cu - Ni couple when alcohol is heated at 180ºC then dehydrohalogenation takes place. As a result, aldehyde and ketone are formed.
H-CH2OH ----> H-CH=O + H2
CH3-CH2OH ----> H-CH=O + H2
(CH3)2-CH-OH ----> (CH3)2-C=O + H2
2. From Oxidation of Alcohol
In presence of oxidizing agents, K2Cr2O7 or concentrated H2SO4, alcohols are oxidized to form aldehyde or ketone.
H-CH2OH + [O] ----> H-CH=O + H2O
CH3-CH2OH + [O] ----> H-CH=O + H2O
(CH3)2-CH-OH + [O] ----> (CH3)2-C=O + H2O
3. From Dry Distillation
By the dry distillation of calsium formate (Calsium salt of formic acid), form aldehyde is obtained.
Ca(COOH)2 ----> HCHO + CaCO3
By the dry distillation of calsium salt of formic acid and calsium salt of carboxylic acid, aldehydes are obtained.
Ca(CH3OOH)2 + Ca(COOH)2 ----> CH3CHO + CaCO3
By the dry distillation of calsium salt of carboxylic acid, Ketone is formed.
Ca(CH3OOH)2 ----> CH3CHO + CaCO3
4. From Ethyne
This method is used for the preparation of acetaldehyde. In presence of catalyst H2SO4 and HgSO4 when ethyne reacts with water than unstable, intermediate vinyle alcohol is formed which on rearrangement of atoms convert into acetaldehyde.
H-C≡C-H + H2O ----> H2C-HCOH ----> H3C-COH
Preparation of Acetone By Pyrolysis of Acetic Acid
In presence of catalyst MnO2, when the acetic acid is heated at about 500ºC then acetone is formed.
CH3COOH ----> CH3-CHO + CO2 + H2O
Uses of Aldehyde
1. Aldehyde is used a preservative for biological specimen, as antiseptic and as disinfectant.
2. It is used in the synthesis of resins and plastics.
3. It is used to prepare drying oils and dyes.
4. It is used in the silvering of mirror.
5. It is used in processing of anti-polio vaccine.
6. It is used to prepare highly explosive cyclonite.
Uses of Ketones
1. It is used as a solvent for organic compounds.
2. It is used for storage of acetylene in solution form.
3. It is used in the preparation of iodoform, chloroform, etc.
4. It is used in the preparation of scent.
5. It is used as nail-polish remover.
6. It is used in the preparation of smokeless gun power and synthetic rubber
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Alcohol ROH
Definition
Organic compounds that contain monovalent functional group OH are called alcohols.
General Formula
Alcohols are denoted by ROH, where R may be any alkyl group. The general formula of aliphatic alcohol is
CnH2n+1 - OH
Where n may be any natural number.
Examples
CH3 - OH | Methyl Alcohol (Methanol)
C2H5 - OH | Ethyl Alcohol (Ethanol)
Classification of Alcohols
On the basis of number of groups, alcohols have been classified into the following.
1. Monohydric Alcohols
2. Dihydric Alcohols
3. Polyhydric Alcohols
1. Monohydric Alcohols (Hydrins)
Those aliphatic compounds that contain only one hydroxyl group (OH) are known as Monohydric Alcohols. They are also known as Hydrins.
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Types of Hydrins
On the basis of carbon atom, monohydric alcohols have been further classified into the following.
a. Primary Alcohols
b. Secondary Alcohols
c. Tertiary Alcohols
a. Primary Alcohols
When one hydrogen atom of methyl group is replaced by any alkyl group, then the carbon atom of the substituted methyl is called Primary carbon atom.
H-CH2- ----> R-CH2-
Those monohydric alcohols in which OH group is directly bonded with primary carbon atom are called Primary Alcohols.
H-CH2-OH ----> R-CH2-OH
b. Secondary Alcohols
When two hydrogen atoms of methyl group are replaced by alkyl groups, then the carbon atom of the substituted methyl is called Secondary carbon atom. These alkyl groups may be different or similar.
H-CH2- ----> R2-CH-
Those monohydric alcohols in which OH group is directly bonded with Secondary carbon atom are called Secondary Alcohols.
H-CH2-OH ----> R2-CH-OH
c. Tertiary Alcohols
When three hydrogen atoms of methyl group are replaced by alkyl groups, then the carbon atom of the substituted methyl is called Tertiary carbon atom. These alkyl groups may be different or similar.
H-CH2- ----> R3C-
Those monohydric alcohols in which OH group is directly bonded with Tertiary carbon atom are called Tertiary Alcohols.
H-CH2-OH ----> R3C-OH
2. Dihydric Alcohols
Those aliphatic compounds that contain two hydroxyl group (OH) are known as dihydric alcohols. They are also known as Glycol.
OH-CH2-CH2-OH
3. Polyhydric Alcohols
Those aliphatic compounds that contain three or more hydroxyl group (OH) are known as Polyhydric Alcohols. They are also known as Glycerol.
OH-CH2 -CHOH-CH2-OH
Preparation
Alcohols can be prepared by the following methods.
1. From Alkene
In presence of catalyst, dilute H2SO4, when ethene reacts with water, then ethyl alcohol or ethanol is formed.
C2H4 + H2O ----> C2H5OH
2. From Grignard's Reagent
The following chemical reaction show the preparation of alcohol from Grignard's Reagent.
3. From Fermentation
On large scale, ethyl alcohol is produced by fermentation. Fermentation means gentle bubbling or boiling. In presence of microorganism enzymes, one compound is converted into other. Carbondioxide gas is evolved in form of bubbles, therefore the process is called fermentation.
Uses
1. Ethanol is used as a solvent. It dissolves a large variety of organic substances such as gums, resins, tincture and varnishes.
2. It is being extensively used in the form of different beverages.
3. It is used as raw material for the preparation of other organic solvents such as CHCl3, ether and esters.
4. It is used as fuel substitute and for low temperature thermometer.
5. Ethanol is used as inert solvent for certain organic reactions and re-crystallization of many organic compounds.
Classification On The Basis Of Composition
On the basis of composition, alcohols have been classified into following types.
1. Absolute Alcohol
Organic compounds that contain 99.99% pure ethyl alcohol are known as absolute alcohols.
2. Rectified Spirit
Organic compounds that contain 92% - 95% ethyl alcohol are known as rectified spirits.
3. Denatured Alcohol
Organic compounds that contain 85% ethyl alcohol, 11% water and 4% methyl alcohol are known as denatured alcohol. They are also known as methylated spirits
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Definition
Organic compounds that contain monovalent functional group OH are called alcohols.
General Formula
Alcohols are denoted by ROH, where R may be any alkyl group. The general formula of aliphatic alcohol is
CnH2n+1 - OH
Where n may be any natural number.
Examples
CH3 - OH | Methyl Alcohol (Methanol)
C2H5 - OH | Ethyl Alcohol (Ethanol)
Classification of Alcohols
On the basis of number of groups, alcohols have been classified into the following.
1. Monohydric Alcohols
2. Dihydric Alcohols
3. Polyhydric Alcohols
1. Monohydric Alcohols (Hydrins)
Those aliphatic compounds that contain only one hydroxyl group (OH) are known as Monohydric Alcohols. They are also known as Hydrins.
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Types of Hydrins
On the basis of carbon atom, monohydric alcohols have been further classified into the following.
a. Primary Alcohols
b. Secondary Alcohols
c. Tertiary Alcohols
a. Primary Alcohols
When one hydrogen atom of methyl group is replaced by any alkyl group, then the carbon atom of the substituted methyl is called Primary carbon atom.
H-CH2- ----> R-CH2-
Those monohydric alcohols in which OH group is directly bonded with primary carbon atom are called Primary Alcohols.
H-CH2-OH ----> R-CH2-OH
b. Secondary Alcohols
When two hydrogen atoms of methyl group are replaced by alkyl groups, then the carbon atom of the substituted methyl is called Secondary carbon atom. These alkyl groups may be different or similar.
H-CH2- ----> R2-CH-
Those monohydric alcohols in which OH group is directly bonded with Secondary carbon atom are called Secondary Alcohols.
H-CH2-OH ----> R2-CH-OH
c. Tertiary Alcohols
When three hydrogen atoms of methyl group are replaced by alkyl groups, then the carbon atom of the substituted methyl is called Tertiary carbon atom. These alkyl groups may be different or similar.
H-CH2- ----> R3C-
Those monohydric alcohols in which OH group is directly bonded with Tertiary carbon atom are called Tertiary Alcohols.
H-CH2-OH ----> R3C-OH
2. Dihydric Alcohols
Those aliphatic compounds that contain two hydroxyl group (OH) are known as dihydric alcohols. They are also known as Glycol.
OH-CH2-CH2-OH
3. Polyhydric Alcohols
Those aliphatic compounds that contain three or more hydroxyl group (OH) are known as Polyhydric Alcohols. They are also known as Glycerol.
OH-CH2 -CHOH-CH2-OH
Preparation
Alcohols can be prepared by the following methods.
1. From Alkene
In presence of catalyst, dilute H2SO4, when ethene reacts with water, then ethyl alcohol or ethanol is formed.
C2H4 + H2O ----> C2H5OH
2. From Grignard's Reagent
The following chemical reaction show the preparation of alcohol from Grignard's Reagent.
3. From Fermentation
On large scale, ethyl alcohol is produced by fermentation. Fermentation means gentle bubbling or boiling. In presence of microorganism enzymes, one compound is converted into other. Carbondioxide gas is evolved in form of bubbles, therefore the process is called fermentation.
Uses
1. Ethanol is used as a solvent. It dissolves a large variety of organic substances such as gums, resins, tincture and varnishes.
2. It is being extensively used in the form of different beverages.
3. It is used as raw material for the preparation of other organic solvents such as CHCl3, ether and esters.
4. It is used as fuel substitute and for low temperature thermometer.
5. Ethanol is used as inert solvent for certain organic reactions and re-crystallization of many organic compounds.
Classification On The Basis Of Composition
On the basis of composition, alcohols have been classified into following types.
1. Absolute Alcohol
Organic compounds that contain 99.99% pure ethyl alcohol are known as absolute alcohols.
2. Rectified Spirit
Organic compounds that contain 92% - 95% ethyl alcohol are known as rectified spirits.
3. Denatured Alcohol
Organic compounds that contain 85% ethyl alcohol, 11% water and 4% methyl alcohol are known as denatured alcohol. They are also known as methylated spirits
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Alkyl Halide
Introduction
Alkyl halides are the derivatives of alkanes, they are denoted by RX where R may be any alkyl group and X may be any halogen atom (Cl, Br, I). The general formula of alkyl halide is given by
CnH2n + 1 - X
Where n may be any natural number and X may be halogen atom.
Definition
When one hydrogen atom of alkane is replaced by halogen atom then the substituted alkane is formed that is known as alkyl halide or mono halo alkane.
Classification of Alkyl Halide
On the basis of carbon atom alkyl halides are classified into following three classes.
1. Primary Alkyl Halide
2. Secondary Alkyl Halide
3. Tertiary Alkyl Halide
1. Primary Alkyl Halide (Iº RX)
When one hydrogen atom of methyl group is replaced by an alkyl group, then the carbon of the substituted methyl is called Primary carbon atom.
H-CH2- ----> R-CH2-
Those alkyl halides in which halogen atom is attached directly with primary carbon atom are called Primary alkyl halides.
H-CH2-X ----> R-CH2-X
2. Secondary Alkyl Halide (2º RX)
When two hydrogen atoms of methyl group are replace by any alkyl group, then the carbon atom of substituted methyl is called secondary carbon atom.
H2-CH- ----> R2-CH-
Those alkyl halides in which halogen atom is directly attached with the secondary carbon atom are called secondary alkyl halides. The alkyl group may be similar or different.
H2-CH-X ----> R2-CH-X
3. Tertiary Alkyl Halide (3º RX)
When three hydrogen atoms of methyl groups are replaced by any alkyl group, then the carbon atom of the substituted methyl is called Tertiary carbon atom.
H3-C- ----> R3-C-
Those alkyl halides in which halogen atom is attached directly with the tertiary carbon atom are called Tertiary Alkyl Halide. The alkyl group of tertiary alkyl halide may be different or similar.
H3-C-X ----> R3-C-X
Chemical Reactions of Alkyl Halide
Alkyl Halides are highly reactive compounds and show variety of chemical reactions. Some important chemical reactions are given below.
1. SN Reactions
2. Formation of Grignard's Reagent
3. Elimination Reactions or E-Reactions
SN Reactiosn
In alkyl halide, the electronegativity of halogen atoms is greater than carbon atom of alkyl group. Therefore, the shared pair of electron between R - X (C-X) is shifted towards halogen atom. As a result halogen becomes partial negativity charged and carbon atom of alkyl group becomes partial positively charged ion.
+R - X
+H3C - Cl-
Those atoms/molecules/ions, which are electron deficient or contain positive charge are called Electrophile. Those atoms/molecules/ions, which are electron rich or contain negative charge are called Nucleophile.
In alkyl halide, alkyl group act as electrophile where as halogen atom act as nucleophile. Those reactions in which one nucleophile is replaced by other nucleophile are called Nucleophillic Substitution Reactions or simply SN Reactions.
When alkyl halide reacts with attacking nucleophile or nucleophilic reagent then halogen atom of alkyl halide is replaced is replaced by attacking nucleophile to form a substituted product.
R-X + Nu- ----> R - Nu + X
H3C Br + CN ----> H3C - CN + Br-
H3C - Br + OH- -----> H3C - OH + Br-
H3C - Br + SH- ----> H3C - SH + Br-
H3C - Br + NH2- ----> H3C - NH2 + Br-
H3C - Br + OR- ----> H3C - Or + Br-
H3C - Br + -OOCR ----> H3C - OOCR + Br-
To be an affective nucleophile in Sn reaction, the attacking nucleophile should be stronger base than the leaving group.
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Classification of SN Reactions
On the basis of Mechanism, SN reactions are classified into following two classes.
1. SN(1) Reactions
2. SN(2) Reactions
1. SN(1) Reactions
Definition
Those nucleophilic substitution reaction in which rate of reaction and formation of product depends upon the concentration of one specie are known as SN(1) Reactions.
Mechanism
The mechanism of SN(1) Reactions proceeds in two steps.
First Step
It is a reversible and slow step, the alkyl halide dissociates into positively charged carbonium ion and negatively charged halide ion (Leaving Group)
Second Step
It is a irreversible and fast step, the attacking nucleophile reacts with the positively charged carbonium to give a final substituted product.
Rate of Reaction
The slow step of a reaction is a rate determining step. In this mechanism, first step is slow and hence is the rate determining step, which shows that the rate of formation of product depends upon the concentration of one molecule i.e. alkyl halide.
Rate of Reaction = K [R - X]
Since the rate of reaction depends upon the concentration of only one molecule, therefore, it is also known as uni-molecular nucleophilic substitution reaction.
Conclusion
In all tertiary alkyl halide, SN reactions proceed through SN(1) mechanism. In all secondary alkyl halides SN reaction may occur through SN(1) mechanism or SN(2) mechanism depending on the nature of the solvent in which the reaction is carried out. Polar solvents help in ionization so they favor SN(1) Reactions.
2. SN(2) Reactions
Definition
Those nucloephillic reactions in which rate of reaction depends upon the concentration of two species is knows as SN(2) Reactions.
Mechanism
The mechanism of SN(2) Reaction occurs through following mechanism.
The attacking nucleophile reacts with carbon atom of alkyl halide to form an intermediate unstable complex, therefore, the formation of C - Nu bond and cleavage of C - X bond occurs simultaneously to form a substituted product and leaving group.
In this mechanism, the attacking nucleophile attacks the carbon atom from opposite side of the halogen atom.
Diagram Coming Soon
Rate pf Reaction
The slow step of reaction is a rate determining step. In this mechanism, the rate of formation of product depends upon the concentration of two species of molecules i.e. alkyl halide and attacking nculeophile.
Rate of Reaction = K [R - X] [Nu-]
Since the rate of reaction depends upon the concentration of two species therefore, it is also known as bimolecular nucleophilic substitution reaction.
Conclusion
In all Primary alkyl halide, SN reactions proceed through SN(2) mechanism. In all secondary alkyl halides SN reaction may occur through SN(1) mechanism or SN(2) mechanism depending on the nature of the solvent in which the reaction is carried out. Polar solvents help in ionization so they favor SN(1) Reactions, where as non polar solvents favours SN(2) mechanism.
Formation of Grignard's Reagent
In presence of dry ether, when alkyl halide reacts with magnesium metal, then alkyl magnesium halide is formed. This compound was first synthesized by Grignard therefore it is known as Grignard's reagent.
Grignard's reagent plays an important role in synthetic organic chemistry because it is used to prepare a variety of organic compounds.
The reaction of Grignard's reagent are explained on the basis that due to metal, magnesium act as electrophile, therefore the bond between C - Mg is polarized. As a result the carbon atom bonded with magnesium bears a partial negative charge and hence act as nucleophile.
The carbon atom of Grignard's reagent (nucleophile) reacts with any electrophillic reagent. As a result the bond between C - Mg is broken and a new bond between carbon and electrophillic reagent is formed.
Elimination Reaction Or E-Reaction Or β Elimination Reactions
Definition
Those reactions in which removal of β hydrogen takes place in an alkyl halide with the formation of double bond are known as β - Eliminates Reaction..
OR
Those reactions in which removal of water molecule takes place with the formation of double bond are also called elimination reactions of simply e-reactions.
Reaction Mechanism
Consider alkyl halide which contains two or more than two carbon atoms. The carbon atoms which is directly bonded with halogen atom is called α-carbon atom. The carbon atom (s) adjacent to α-carbon atom is called β - carbon atom and so on.
The hydrogen atom which is directly attached with α - carbon atom are known as α - hydrogen atom. The hydrogen atom which is directly bonded with β - carbon are known as β - hydrogen atom and so on.
In alkyl halide the electro negativity of halogen atom is more than the carbon of alkyl group. As a result the shared pair of electron between C - X is shifted towards Halogen atom. As a result halogen becomes partial positive ion. Now α - carbon pulled the electron of β - carbon and β - carbon pulled the electron of β - hydrogen atom. Therefore, ultimately the positive charge is shifted to β - hydrogen atom.
Thus, the nucleophile or base i.e. OH- attacks β - hydrogen atom. As a result water molecule is formed with the removal of β - hydrogen atom. The bond between α - carbon and β - carbon takes place simultaneously.
Due to the removal of β - hydrogen atom the elimination is also called β - elimination reaction.
Example
When alkyl is heated with alcoholic potash then dehydrohalogenation takes place. As a result, Alkene is formed with elimination of water molecule.
RC2H4X + KOH ----> RHC = CH2 + H2O + KX
Alkene
HC2H4Cl + KOH ----> H2C = CH2 + H2O + KCl
Ethene
Classification of Elimination Reactions
On the basis of mechanism, elimination reactions are classified into the following two classes.
1. E(1) Reaction.
2. E(2) Reaction.
1. E(1) Reaction
Definition
Those elimination reactions in which the rate of reaction depends upon the concentration of one substance or molecule are known as E(1) Reactions.
Mechanism
The mechanism of E1 Reactions occur through following two steps.
First Step
It is a slow and reversible step. Alkyl halide is dissociated into carbonium ion and halide ion.
Second Step
It is a irreversible and fast step, the attacking (OH-) removes a proton (H+) from the β - carbon atom with the simultaneous formation of double bond between α - carbon atom and β - carbon atom.
Rate of Reaction
The slow step of a reaction is rate determining step. In this mechanism the rate of reaction depends upon the first step or on the concentration of only one molecule, i.e. alkyl halide.
Rate of Reaction = K [R - X]
Since the rate of reaction depends upon the concentration of only one substance or molecule, therefore, it is called uni-molecular elimination reaction or simply E(1) Reaction, where 1 stands for uni-molecular.
Conclusion
In all tertiary halides, elimination reaction occurs through E(1) mechanism. In all secondary alkyl halides elimination reaction may occur through both E(1) and E(2) mechanism, which depends upon the nature of the solvent in which the reaction is carried out. The presence of polar solvent favours E(1) mechanism.
2. E(2) Reactions
Definition
Those elimination reactions in which rate of reaction depends upon the concentration of two substances or molecules is known as E(2) Reactions.
Mechanism
The mechanism of E(2) reaction, occur through the following single step. Due to high electronegativity of halogen atom the shared pair of electron between C - X is shifted towards halogen atom. As a result halogen becomes partial negativity charged and α - carbon atom becomes partial positively charged ion. Ultimately, the positive charge is shifted to β - hydrogen to form unstable intermediate transition stage. Immediately the cleavage of C(β) - H and C(α) - H bond takes place simultaneously. As a result double bond is formed between α - carbon atom and β - carbon with the elimination of water molecule.
OH + H3C-CR2+ ----> Transition Stage ----> H2C=CR2 + H2O
Rate of Reaction
The slow step of reaction is a rate determining step. In this mechanism rate of reaction depends upon the concentration of two species, i.e. alkyl halide and base.
Rate of Reaction = K [R - X] [OH-]
Since the rate of reaction depends upon the concentration of two species therefore it is called bimolecular elimination reaction or simply E(2) reaction where 2 stands for bimolecular.
Conclusion
In all primary alkyl halides, elimination reaction occurs through E(2) mechanism. In all secondary alkyl halides elimination reaction may occur through both E(1) and E(2) mechanism, which depends upon the nature of the solvent in which the reaction is carried out. The presence of polar solvent favours E(1) mechanism, whereas non-polar solvent favours E(2) mechanism
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Introduction
Alkyl halides are the derivatives of alkanes, they are denoted by RX where R may be any alkyl group and X may be any halogen atom (Cl, Br, I). The general formula of alkyl halide is given by
CnH2n + 1 - X
Where n may be any natural number and X may be halogen atom.
Definition
When one hydrogen atom of alkane is replaced by halogen atom then the substituted alkane is formed that is known as alkyl halide or mono halo alkane.
Classification of Alkyl Halide
On the basis of carbon atom alkyl halides are classified into following three classes.
1. Primary Alkyl Halide
2. Secondary Alkyl Halide
3. Tertiary Alkyl Halide
1. Primary Alkyl Halide (Iº RX)
When one hydrogen atom of methyl group is replaced by an alkyl group, then the carbon of the substituted methyl is called Primary carbon atom.
H-CH2- ----> R-CH2-
Those alkyl halides in which halogen atom is attached directly with primary carbon atom are called Primary alkyl halides.
H-CH2-X ----> R-CH2-X
2. Secondary Alkyl Halide (2º RX)
When two hydrogen atoms of methyl group are replace by any alkyl group, then the carbon atom of substituted methyl is called secondary carbon atom.
H2-CH- ----> R2-CH-
Those alkyl halides in which halogen atom is directly attached with the secondary carbon atom are called secondary alkyl halides. The alkyl group may be similar or different.
H2-CH-X ----> R2-CH-X
3. Tertiary Alkyl Halide (3º RX)
When three hydrogen atoms of methyl groups are replaced by any alkyl group, then the carbon atom of the substituted methyl is called Tertiary carbon atom.
H3-C- ----> R3-C-
Those alkyl halides in which halogen atom is attached directly with the tertiary carbon atom are called Tertiary Alkyl Halide. The alkyl group of tertiary alkyl halide may be different or similar.
H3-C-X ----> R3-C-X
Chemical Reactions of Alkyl Halide
Alkyl Halides are highly reactive compounds and show variety of chemical reactions. Some important chemical reactions are given below.
1. SN Reactions
2. Formation of Grignard's Reagent
3. Elimination Reactions or E-Reactions
SN Reactiosn
In alkyl halide, the electronegativity of halogen atoms is greater than carbon atom of alkyl group. Therefore, the shared pair of electron between R - X (C-X) is shifted towards halogen atom. As a result halogen becomes partial negativity charged and carbon atom of alkyl group becomes partial positively charged ion.
+R - X
+H3C - Cl-
Those atoms/molecules/ions, which are electron deficient or contain positive charge are called Electrophile. Those atoms/molecules/ions, which are electron rich or contain negative charge are called Nucleophile.
In alkyl halide, alkyl group act as electrophile where as halogen atom act as nucleophile. Those reactions in which one nucleophile is replaced by other nucleophile are called Nucleophillic Substitution Reactions or simply SN Reactions.
When alkyl halide reacts with attacking nucleophile or nucleophilic reagent then halogen atom of alkyl halide is replaced is replaced by attacking nucleophile to form a substituted product.
R-X + Nu- ----> R - Nu + X
H3C Br + CN ----> H3C - CN + Br-
H3C - Br + OH- -----> H3C - OH + Br-
H3C - Br + SH- ----> H3C - SH + Br-
H3C - Br + NH2- ----> H3C - NH2 + Br-
H3C - Br + OR- ----> H3C - Or + Br-
H3C - Br + -OOCR ----> H3C - OOCR + Br-
To be an affective nucleophile in Sn reaction, the attacking nucleophile should be stronger base than the leaving group.
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Classification of SN Reactions
On the basis of Mechanism, SN reactions are classified into following two classes.
1. SN(1) Reactions
2. SN(2) Reactions
1. SN(1) Reactions
Definition
Those nucleophilic substitution reaction in which rate of reaction and formation of product depends upon the concentration of one specie are known as SN(1) Reactions.
Mechanism
The mechanism of SN(1) Reactions proceeds in two steps.
First Step
It is a reversible and slow step, the alkyl halide dissociates into positively charged carbonium ion and negatively charged halide ion (Leaving Group)
Second Step
It is a irreversible and fast step, the attacking nucleophile reacts with the positively charged carbonium to give a final substituted product.
Rate of Reaction
The slow step of a reaction is a rate determining step. In this mechanism, first step is slow and hence is the rate determining step, which shows that the rate of formation of product depends upon the concentration of one molecule i.e. alkyl halide.
Rate of Reaction = K [R - X]
Since the rate of reaction depends upon the concentration of only one molecule, therefore, it is also known as uni-molecular nucleophilic substitution reaction.
Conclusion
In all tertiary alkyl halide, SN reactions proceed through SN(1) mechanism. In all secondary alkyl halides SN reaction may occur through SN(1) mechanism or SN(2) mechanism depending on the nature of the solvent in which the reaction is carried out. Polar solvents help in ionization so they favor SN(1) Reactions.
2. SN(2) Reactions
Definition
Those nucloephillic reactions in which rate of reaction depends upon the concentration of two species is knows as SN(2) Reactions.
Mechanism
The mechanism of SN(2) Reaction occurs through following mechanism.
The attacking nucleophile reacts with carbon atom of alkyl halide to form an intermediate unstable complex, therefore, the formation of C - Nu bond and cleavage of C - X bond occurs simultaneously to form a substituted product and leaving group.
In this mechanism, the attacking nucleophile attacks the carbon atom from opposite side of the halogen atom.
Diagram Coming Soon
Rate pf Reaction
The slow step of reaction is a rate determining step. In this mechanism, the rate of formation of product depends upon the concentration of two species of molecules i.e. alkyl halide and attacking nculeophile.
Rate of Reaction = K [R - X] [Nu-]
Since the rate of reaction depends upon the concentration of two species therefore, it is also known as bimolecular nucleophilic substitution reaction.
Conclusion
In all Primary alkyl halide, SN reactions proceed through SN(2) mechanism. In all secondary alkyl halides SN reaction may occur through SN(1) mechanism or SN(2) mechanism depending on the nature of the solvent in which the reaction is carried out. Polar solvents help in ionization so they favor SN(1) Reactions, where as non polar solvents favours SN(2) mechanism.
Formation of Grignard's Reagent
In presence of dry ether, when alkyl halide reacts with magnesium metal, then alkyl magnesium halide is formed. This compound was first synthesized by Grignard therefore it is known as Grignard's reagent.
Grignard's reagent plays an important role in synthetic organic chemistry because it is used to prepare a variety of organic compounds.
The reaction of Grignard's reagent are explained on the basis that due to metal, magnesium act as electrophile, therefore the bond between C - Mg is polarized. As a result the carbon atom bonded with magnesium bears a partial negative charge and hence act as nucleophile.
The carbon atom of Grignard's reagent (nucleophile) reacts with any electrophillic reagent. As a result the bond between C - Mg is broken and a new bond between carbon and electrophillic reagent is formed.
Elimination Reaction Or E-Reaction Or β Elimination Reactions
Definition
Those reactions in which removal of β hydrogen takes place in an alkyl halide with the formation of double bond are known as β - Eliminates Reaction..
OR
Those reactions in which removal of water molecule takes place with the formation of double bond are also called elimination reactions of simply e-reactions.
Reaction Mechanism
Consider alkyl halide which contains two or more than two carbon atoms. The carbon atoms which is directly bonded with halogen atom is called α-carbon atom. The carbon atom (s) adjacent to α-carbon atom is called β - carbon atom and so on.
The hydrogen atom which is directly attached with α - carbon atom are known as α - hydrogen atom. The hydrogen atom which is directly bonded with β - carbon are known as β - hydrogen atom and so on.
In alkyl halide the electro negativity of halogen atom is more than the carbon of alkyl group. As a result the shared pair of electron between C - X is shifted towards Halogen atom. As a result halogen becomes partial positive ion. Now α - carbon pulled the electron of β - carbon and β - carbon pulled the electron of β - hydrogen atom. Therefore, ultimately the positive charge is shifted to β - hydrogen atom.
Thus, the nucleophile or base i.e. OH- attacks β - hydrogen atom. As a result water molecule is formed with the removal of β - hydrogen atom. The bond between α - carbon and β - carbon takes place simultaneously.
Due to the removal of β - hydrogen atom the elimination is also called β - elimination reaction.
Example
When alkyl is heated with alcoholic potash then dehydrohalogenation takes place. As a result, Alkene is formed with elimination of water molecule.
RC2H4X + KOH ----> RHC = CH2 + H2O + KX
Alkene
HC2H4Cl + KOH ----> H2C = CH2 + H2O + KCl
Ethene
Classification of Elimination Reactions
On the basis of mechanism, elimination reactions are classified into the following two classes.
1. E(1) Reaction.
2. E(2) Reaction.
1. E(1) Reaction
Definition
Those elimination reactions in which the rate of reaction depends upon the concentration of one substance or molecule are known as E(1) Reactions.
Mechanism
The mechanism of E1 Reactions occur through following two steps.
First Step
It is a slow and reversible step. Alkyl halide is dissociated into carbonium ion and halide ion.
Second Step
It is a irreversible and fast step, the attacking (OH-) removes a proton (H+) from the β - carbon atom with the simultaneous formation of double bond between α - carbon atom and β - carbon atom.
Rate of Reaction
The slow step of a reaction is rate determining step. In this mechanism the rate of reaction depends upon the first step or on the concentration of only one molecule, i.e. alkyl halide.
Rate of Reaction = K [R - X]
Since the rate of reaction depends upon the concentration of only one substance or molecule, therefore, it is called uni-molecular elimination reaction or simply E(1) Reaction, where 1 stands for uni-molecular.
Conclusion
In all tertiary halides, elimination reaction occurs through E(1) mechanism. In all secondary alkyl halides elimination reaction may occur through both E(1) and E(2) mechanism, which depends upon the nature of the solvent in which the reaction is carried out. The presence of polar solvent favours E(1) mechanism.
2. E(2) Reactions
Definition
Those elimination reactions in which rate of reaction depends upon the concentration of two substances or molecules is known as E(2) Reactions.
Mechanism
The mechanism of E(2) reaction, occur through the following single step. Due to high electronegativity of halogen atom the shared pair of electron between C - X is shifted towards halogen atom. As a result halogen becomes partial negativity charged and α - carbon atom becomes partial positively charged ion. Ultimately, the positive charge is shifted to β - hydrogen to form unstable intermediate transition stage. Immediately the cleavage of C(β) - H and C(α) - H bond takes place simultaneously. As a result double bond is formed between α - carbon atom and β - carbon with the elimination of water molecule.
OH + H3C-CR2+ ----> Transition Stage ----> H2C=CR2 + H2O
Rate of Reaction
The slow step of reaction is a rate determining step. In this mechanism rate of reaction depends upon the concentration of two species, i.e. alkyl halide and base.
Rate of Reaction = K [R - X] [OH-]
Since the rate of reaction depends upon the concentration of two species therefore it is called bimolecular elimination reaction or simply E(2) reaction where 2 stands for bimolecular.
Conclusion
In all primary alkyl halides, elimination reaction occurs through E(2) mechanism. In all secondary alkyl halides elimination reaction may occur through both E(1) and E(2) mechanism, which depends upon the nature of the solvent in which the reaction is carried out. The presence of polar solvent favours E(1) mechanism, whereas non-polar solvent favours E(2) mechanism
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Ethyne C2H2
Introduction
Organic compounds, which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are not fulfilled by hydrogen atoms and triple bond is present between two carbon atoms are known as Unsaturated Hydrocarbon or alkynes.
The first member of alkyne family composed of two carbon and two hydrogen atoms and is known as Ethyne or Acetylene.
Structure of Ethyne
Ethyne is a unsaturated hydrocarbon, which is composed of two carbon and two hydrogen atoms. Its molecular formula is C2H2. The structural formula of ethyne shows that each carbon contains one hydrogen atom and triple bond is present between two carbon atoms.
HC ≡ CH
Each carbon atom of ethyne is Sp hyberidized which contains two equivalent partially fill Sp hybrid orbitals and two unhyberidized P orbital. The hybrid orbitals are arranged at the two corners of linear structure with an angle of 180º.
One Sp hybrid orbitals of each carbon atoms overlap with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp - S orbitals. The remaining Sp hybrid of each carbon atom overlap with the Sp hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp - Sp.
The unhyberidized P orbital of each carbon atom are situated perpendicular to the Sp plane and parallel to the unhyberidized Pz orbitals of other carbon atom. The unhyberidized P orbitals of two different carbon atoms overlap side by side to form pi bonds between carbon atoms.
Diagram Coming Soon Therfore in ethyne one sigma and two pi bonds are present between carbon atoms.
Diagram Coming Soon
Preparation of Ethyne
Ethyne can be prepared by the following methods.
1. From Dehalogenation of Tetra Halo Ethane
Removal of halogen from a compound is called Dehalogenation. When tetra halo ethane reacts with powdered zinc metal, then dehalogenation takes place as a result ethyne is formed.
C2H2X4 + 2Zn ----> HC ≡ CH + 2ZnX2
C2H2Cl4 + 2Zn ----> HC ≡ CH + 2ZnCl2
2. From Dehydrohalogenation of Vicinal Dihalide
Removal of hydrogen halide from a compound is called Dehydrogenation. Those dihalides in which halogen atoms are present at two adjacent carbon atoms are called vicinal di halides. When vicinal dihalide (1, 2 - dihalo ethane) reacts with alcoholic potash (KOH) then dehydrohalogenation takes place as a result ethyne is formed.
C2H4X2 + 2KOH ----> HC ≡ CH + 2H2O + 2KX
C2H4Cl2 + 2KOH ----> HC ≡ CH + 2H2O + 2KCl
3. From Calcium Carbide
When Calcium Carbide (CaC2) reacts with cold water then ethyne is formed.
Physical Properties
1. At ordinary temperature and pressure, ethyne exist as colourless gas with sweet smell.
2. Ethyne gas is sparingly soluble in water but easily soluble in organic solvents.
3. It is less denser than air.
4. Liquid ethyne is unstable in nature.
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Chemical Properties
Ethyne is unsaturated hydrocarbon which is composed of two carbon and two hydrogen atoms, its molecular formula is C2H2, the structural formula shows that each carbon contains one hydrogen atom and triple bond is present between two carbon atoms in which one is sigma and two are pi bonds.
When any attacking molecule reacts with ethyne or Acetylene then triple bond is broken into double bond and then single bond, as a result four valencies are set free (two at each carbon atom), now the attacking molecule occupies free valencies to form addition product.
HC ≡ CH ----> HC = CH ----> H2C - CH2
Due to presence of pi electrons ethyne or Acetylene acts a nucleophile. The distance between two carbon atoms in ethyne
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Introduction
Organic compounds, which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are not fulfilled by hydrogen atoms and triple bond is present between two carbon atoms are known as Unsaturated Hydrocarbon or alkynes.
The first member of alkyne family composed of two carbon and two hydrogen atoms and is known as Ethyne or Acetylene.
Structure of Ethyne
Ethyne is a unsaturated hydrocarbon, which is composed of two carbon and two hydrogen atoms. Its molecular formula is C2H2. The structural formula of ethyne shows that each carbon contains one hydrogen atom and triple bond is present between two carbon atoms.
HC ≡ CH
Each carbon atom of ethyne is Sp hyberidized which contains two equivalent partially fill Sp hybrid orbitals and two unhyberidized P orbital. The hybrid orbitals are arranged at the two corners of linear structure with an angle of 180º.
One Sp hybrid orbitals of each carbon atoms overlap with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp - S orbitals. The remaining Sp hybrid of each carbon atom overlap with the Sp hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp - Sp.
The unhyberidized P orbital of each carbon atom are situated perpendicular to the Sp plane and parallel to the unhyberidized Pz orbitals of other carbon atom. The unhyberidized P orbitals of two different carbon atoms overlap side by side to form pi bonds between carbon atoms.
Diagram Coming Soon Therfore in ethyne one sigma and two pi bonds are present between carbon atoms.
Diagram Coming Soon
Preparation of Ethyne
Ethyne can be prepared by the following methods.
1. From Dehalogenation of Tetra Halo Ethane
Removal of halogen from a compound is called Dehalogenation. When tetra halo ethane reacts with powdered zinc metal, then dehalogenation takes place as a result ethyne is formed.
C2H2X4 + 2Zn ----> HC ≡ CH + 2ZnX2
C2H2Cl4 + 2Zn ----> HC ≡ CH + 2ZnCl2
2. From Dehydrohalogenation of Vicinal Dihalide
Removal of hydrogen halide from a compound is called Dehydrogenation. Those dihalides in which halogen atoms are present at two adjacent carbon atoms are called vicinal di halides. When vicinal dihalide (1, 2 - dihalo ethane) reacts with alcoholic potash (KOH) then dehydrohalogenation takes place as a result ethyne is formed.
C2H4X2 + 2KOH ----> HC ≡ CH + 2H2O + 2KX
C2H4Cl2 + 2KOH ----> HC ≡ CH + 2H2O + 2KCl
3. From Calcium Carbide
When Calcium Carbide (CaC2) reacts with cold water then ethyne is formed.
Physical Properties
1. At ordinary temperature and pressure, ethyne exist as colourless gas with sweet smell.
2. Ethyne gas is sparingly soluble in water but easily soluble in organic solvents.
3. It is less denser than air.
4. Liquid ethyne is unstable in nature.
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Chemical Properties
Ethyne is unsaturated hydrocarbon which is composed of two carbon and two hydrogen atoms, its molecular formula is C2H2, the structural formula shows that each carbon contains one hydrogen atom and triple bond is present between two carbon atoms in which one is sigma and two are pi bonds.
When any attacking molecule reacts with ethyne or Acetylene then triple bond is broken into double bond and then single bond, as a result four valencies are set free (two at each carbon atom), now the attacking molecule occupies free valencies to form addition product.
HC ≡ CH ----> HC = CH ----> H2C - CH2
Due to presence of pi electrons ethyne or Acetylene acts a nucleophile. The distance between two carbon atoms in ethyne
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Ethene C2H4
Introduction
Organic compounds which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are not fulfilled by hydrogen atoms and double bonds are present between carbon atoms are called Unsaturated Hydrocarbon or alkenes.
The first member of alkene family composed of two carbon and four hydrogen atoms and is known as Ethene.
Structure of Ethene
Ethene is an unsaturated hydracarbon, which is composed of two carbon and four hydrogen atoms. Its molecular formula is C2H4. The structural formula of ethene shows that each carbon contains two hydrogen and double bond is present two carbon atoms.
H2C = CH2
Each carbon atom of ethene is Sp2 hyberidized which contains three equivalent partially filled Sp2 hybrid orbitals and unhyberidized Pz orbital. The hybrid orbitals are arranged at the three corners of coplaner triangle with an angle of 120º.
Two Sp2 hybrid orbitals of carbon atoms overlapp with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp2 - S orbitals. The remaining Sp2 hybrid of each carbon atom overlapp with the Sp2 hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp2 - Sp2.
The unhyberidized Pz orbital of each carbon atom are situated perpendicular to the Sp2 plane and parallel to the unhyberidized Pz orbitals of two different carbon atoms overlap side by side to form a pi bond between carbon atoms.
Diagram Coming Soon
Preparation of Ethene
Ethene can be prepared by the following methods.
1. From Dehydrohalogenation of Ethyl Halide
Removal of hydrogen halide from a compound is called Dehydrogenation. When mono halo ethane or ethyl halide is treated with alcoholic potash (KOH), then dehydrohalogenation takes place as a result ethene is formed.
C2H5X + KOH ----> H2C = CH2 + H2O + KX
C2H5Cl + KOH ----> H2C = CH2 + H2O + KCl
2. From Dehalogenation Of Vicinal Dihalide
Removal of halogen from a compound is called Dehalogenation. Those dihalides in which hydrogen atoms are attached with two adjacent carbon atoms are called Vicinal Dihalide or 1, 2 - dihalo ethane reacts with powdered zinc metal then dehalogenation takes place as a result Ethene is formed.
C2H4X2 + Zn ----> C2H4 + ZnX2
C2H4Cl2 + Zn ----> C2H4 + ZnCl2
3. From Dehydration of Ethyl Alcohol (Ethanol)
Removal of water molecule from a compound is called Dehydration. In presence of catalyst concentrated H2SO4, when ethyl alcohol or ethanol is heated at about 170ºC then Dehydration takes place as a result ethene is formed.
C2H5OH ----> C2H4 + H2O
Dehydration of ethanol can also be called out in following two ways.
1. In presence of catalyst Al2O3 when ethanol is heated at (350 - 360ºC), then ethene is formed
C2H5OH ----> C2H4 + H2O
2. In presence of mixture of Al2O3 and H3PO4 at 250ºC, when ethanol is heated then ethene is formed.
C2H5OH ----> C2H4 + H2O
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4. From Hydrogenation of Ethyne
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst Ni, Pt, Pd, when ethyne is heated with limited amount of Hydrogen at 250ºC then hydrogenation takes place as a result ethene is formed
H-C ≡ C - H + H2 ----> H2C = CH2
Physical Properties of Ethene
1. At ordinary temperature and pressure ethene exist as colourless gas with sweet smell.
2. It is slightly soluble in water but easily soluble in organic solvent.
3. Ethene gas is less denser than air.
4. Ethene gas produces Anaesthesia on inhilation.
Chemical Properties of Ethene
Ethene is unsaturated hydrocarbon which is composed of two carbon and four hydrogen atoms. Its molecular formula is C2H4. The structural formula shows that double bond is present between two carbon atoms in which one is sigma and other is pi bond.
Sigma bond is formed by the direct overlapping of orbitals and large amount of heat is required to break it. Where as pi bond is formed by the side by side overlapping of orbital and less amount of heat is required to break it. Hence sigma bond is stronger than pi bond.
When any attacking molecule reacts with ethene then double bond is broken into sigma bond (sigma bond) as a result two valencies are set free (one at each carbon). Now the attacking molecule occupies free valencies to form addition product.
H-C ≡ C-H + AB ----> H2CA - BCH2
Those atoms, molecules and ions, which are electron rich or contain negative charge are called Nucleophile. Those atoms, molecules or ion, which are electron defficient or contain positive charge are called Electrophile. Since pi electrons are present in ethene therefore it acts as Nucleophile. It reacts with any electrophillic reagent to form addition product. Hence the addition reactions of ethene are also called Electrophilic Addition Reaction.
Some important reactions of ethene are given below.
1. Hydrogenation
Introduction of Hydrogen in a compound is called Hydrogenation. In presence of catalyst Ni/Pt/Pd, when ethene is heated at about 250ºC then hydrogenation takes place as a result ethane is formed
H-C ≡ C-H \ H2 ----> H3C-CH3
2. Halogenation
Introduction of halogen in a compound is called Halogenation. When ethene reacts with halogen then halogenation takes place as a result di halo ethane is formed.
C2H4 + X2 ----> C2H4X2
The order of reactivity of halogen is Cl2 > Br2 > I2. It means that Cl2 and Br2 reacts at room temperature where as I2 reacts only in presence of catalyst C2H5OH.
C2H4 + Cl2 ----> C2H4Cl2
C2H4 + Br2 ----> C2H4Br2
3. Hydrohalogenation
Introduction of hydrogen halide (HX) in a compound is called Hydro Halogenation. When Halogen acid reacts with ethene the hydro halogenation takes place. As a result addition product mono halo ethane or ethyl halide is formed.
C2H4 + HX + C2H5X
The order of reactivity of halogen acid is HI > HBR ? HCl
C2H4 + HBr ----> C2H5Br
4. Addition of Water
In presence of catalyst concentrated H2SO4, when ethene reacts with water then ethyl alcohol or ethanol is formed.
C2H4 + H2O ----> C2H5OH
5. Addition of H2SO4
When ethene reacts with cold concentrated H2SO4 then ethyl hydrogen sulphate is formed.
6. Addition of Hypohalous Acid (HOX)
When halogen dissolves in water then halogen acid and hypohalous acid are formed.
X2 + H2O ----> HX + HOX
Cl2 + H20 ----> HCl + HOCl
When ethene reacts with hypohalous acid then ethane halohydrin is formed.
C2H4 + HOX ----> C2H4 - OH-X
7. Oxidation
When ethene is oxidized by dilute and alkaline solution of KMnO4 then ethylene glycol (1, 2 - ethandiol) is formed. As a result of this reaction purple colour of KmnO4 is decolourized. Therefore this test is used to distinguish between ethene in laboratory.
C2H4 + HOH ----> C2H4(OH)2
8. Combustion
When ethene is burnt in presence of air or oxygen, then carbon dioxide and water are formed with the evolution of large amount of heat energy.
C2H4 + 3O2 ----> 2CO2 + 2H2O -ΔH
9. Formation of Mustard Gas
When ethene reacts with sulphur mono chloride then mustard gas is formed which is highly poisonous gas.
C2H4 + S2Cl2 ----> S(CH2-CH2-Cl)2 + S
10. Polymerization
The phenomenon in which simpler and smaller molecules are converted into large and complex molecules is called Polymerization. The simple and smaller is called Monomer, where as large and complex molecule is called Polymer.
In presence of traces of oxygen, when ethene is heated at 200ºC under 1000 atm pressure then polymerization takes place as a result poly ethene is formed.
Diagram Coming Soon
Uses of Ethene
1. Ethene gas is used as fuel
2. Ethene gas is used as Anaesthetic.
3. Ethene gas is used in manufacture of plastics mustard gas etc.
4. Ethene gas is used for artificial ripening of raw fruit.
Read more: Ethene C2H4 http://www.friendsmania.net/forum/2nd-year-chemistry-notes/25760.htm#ixzz34b1p0MFH
Introduction
Organic compounds which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are not fulfilled by hydrogen atoms and double bonds are present between carbon atoms are called Unsaturated Hydrocarbon or alkenes.
The first member of alkene family composed of two carbon and four hydrogen atoms and is known as Ethene.
Structure of Ethene
Ethene is an unsaturated hydracarbon, which is composed of two carbon and four hydrogen atoms. Its molecular formula is C2H4. The structural formula of ethene shows that each carbon contains two hydrogen and double bond is present two carbon atoms.
H2C = CH2
Each carbon atom of ethene is Sp2 hyberidized which contains three equivalent partially filled Sp2 hybrid orbitals and unhyberidized Pz orbital. The hybrid orbitals are arranged at the three corners of coplaner triangle with an angle of 120º.
Two Sp2 hybrid orbitals of carbon atoms overlapp with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp2 - S orbitals. The remaining Sp2 hybrid of each carbon atom overlapp with the Sp2 hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp2 - Sp2.
The unhyberidized Pz orbital of each carbon atom are situated perpendicular to the Sp2 plane and parallel to the unhyberidized Pz orbitals of two different carbon atoms overlap side by side to form a pi bond between carbon atoms.
Diagram Coming Soon
Preparation of Ethene
Ethene can be prepared by the following methods.
1. From Dehydrohalogenation of Ethyl Halide
Removal of hydrogen halide from a compound is called Dehydrogenation. When mono halo ethane or ethyl halide is treated with alcoholic potash (KOH), then dehydrohalogenation takes place as a result ethene is formed.
C2H5X + KOH ----> H2C = CH2 + H2O + KX
C2H5Cl + KOH ----> H2C = CH2 + H2O + KCl
2. From Dehalogenation Of Vicinal Dihalide
Removal of halogen from a compound is called Dehalogenation. Those dihalides in which hydrogen atoms are attached with two adjacent carbon atoms are called Vicinal Dihalide or 1, 2 - dihalo ethane reacts with powdered zinc metal then dehalogenation takes place as a result Ethene is formed.
C2H4X2 + Zn ----> C2H4 + ZnX2
C2H4Cl2 + Zn ----> C2H4 + ZnCl2
3. From Dehydration of Ethyl Alcohol (Ethanol)
Removal of water molecule from a compound is called Dehydration. In presence of catalyst concentrated H2SO4, when ethyl alcohol or ethanol is heated at about 170ºC then Dehydration takes place as a result ethene is formed.
C2H5OH ----> C2H4 + H2O
Dehydration of ethanol can also be called out in following two ways.
1. In presence of catalyst Al2O3 when ethanol is heated at (350 - 360ºC), then ethene is formed
C2H5OH ----> C2H4 + H2O
2. In presence of mixture of Al2O3 and H3PO4 at 250ºC, when ethanol is heated then ethene is formed.
C2H5OH ----> C2H4 + H2O
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4. From Hydrogenation of Ethyne
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst Ni, Pt, Pd, when ethyne is heated with limited amount of Hydrogen at 250ºC then hydrogenation takes place as a result ethene is formed
H-C ≡ C - H + H2 ----> H2C = CH2
Physical Properties of Ethene
1. At ordinary temperature and pressure ethene exist as colourless gas with sweet smell.
2. It is slightly soluble in water but easily soluble in organic solvent.
3. Ethene gas is less denser than air.
4. Ethene gas produces Anaesthesia on inhilation.
Chemical Properties of Ethene
Ethene is unsaturated hydrocarbon which is composed of two carbon and four hydrogen atoms. Its molecular formula is C2H4. The structural formula shows that double bond is present between two carbon atoms in which one is sigma and other is pi bond.
Sigma bond is formed by the direct overlapping of orbitals and large amount of heat is required to break it. Where as pi bond is formed by the side by side overlapping of orbital and less amount of heat is required to break it. Hence sigma bond is stronger than pi bond.
When any attacking molecule reacts with ethene then double bond is broken into sigma bond (sigma bond) as a result two valencies are set free (one at each carbon). Now the attacking molecule occupies free valencies to form addition product.
H-C ≡ C-H + AB ----> H2CA - BCH2
Those atoms, molecules and ions, which are electron rich or contain negative charge are called Nucleophile. Those atoms, molecules or ion, which are electron defficient or contain positive charge are called Electrophile. Since pi electrons are present in ethene therefore it acts as Nucleophile. It reacts with any electrophillic reagent to form addition product. Hence the addition reactions of ethene are also called Electrophilic Addition Reaction.
Some important reactions of ethene are given below.
1. Hydrogenation
Introduction of Hydrogen in a compound is called Hydrogenation. In presence of catalyst Ni/Pt/Pd, when ethene is heated at about 250ºC then hydrogenation takes place as a result ethane is formed
H-C ≡ C-H \ H2 ----> H3C-CH3
2. Halogenation
Introduction of halogen in a compound is called Halogenation. When ethene reacts with halogen then halogenation takes place as a result di halo ethane is formed.
C2H4 + X2 ----> C2H4X2
The order of reactivity of halogen is Cl2 > Br2 > I2. It means that Cl2 and Br2 reacts at room temperature where as I2 reacts only in presence of catalyst C2H5OH.
C2H4 + Cl2 ----> C2H4Cl2
C2H4 + Br2 ----> C2H4Br2
3. Hydrohalogenation
Introduction of hydrogen halide (HX) in a compound is called Hydro Halogenation. When Halogen acid reacts with ethene the hydro halogenation takes place. As a result addition product mono halo ethane or ethyl halide is formed.
C2H4 + HX + C2H5X
The order of reactivity of halogen acid is HI > HBR ? HCl
C2H4 + HBr ----> C2H5Br
4. Addition of Water
In presence of catalyst concentrated H2SO4, when ethene reacts with water then ethyl alcohol or ethanol is formed.
C2H4 + H2O ----> C2H5OH
5. Addition of H2SO4
When ethene reacts with cold concentrated H2SO4 then ethyl hydrogen sulphate is formed.
6. Addition of Hypohalous Acid (HOX)
When halogen dissolves in water then halogen acid and hypohalous acid are formed.
X2 + H2O ----> HX + HOX
Cl2 + H20 ----> HCl + HOCl
When ethene reacts with hypohalous acid then ethane halohydrin is formed.
C2H4 + HOX ----> C2H4 - OH-X
7. Oxidation
When ethene is oxidized by dilute and alkaline solution of KMnO4 then ethylene glycol (1, 2 - ethandiol) is formed. As a result of this reaction purple colour of KmnO4 is decolourized. Therefore this test is used to distinguish between ethene in laboratory.
C2H4 + HOH ----> C2H4(OH)2
8. Combustion
When ethene is burnt in presence of air or oxygen, then carbon dioxide and water are formed with the evolution of large amount of heat energy.
C2H4 + 3O2 ----> 2CO2 + 2H2O -ΔH
9. Formation of Mustard Gas
When ethene reacts with sulphur mono chloride then mustard gas is formed which is highly poisonous gas.
C2H4 + S2Cl2 ----> S(CH2-CH2-Cl)2 + S
10. Polymerization
The phenomenon in which simpler and smaller molecules are converted into large and complex molecules is called Polymerization. The simple and smaller is called Monomer, where as large and complex molecule is called Polymer.
In presence of traces of oxygen, when ethene is heated at 200ºC under 1000 atm pressure then polymerization takes place as a result poly ethene is formed.
Diagram Coming Soon
Uses of Ethene
1. Ethene gas is used as fuel
2. Ethene gas is used as Anaesthetic.
3. Ethene gas is used in manufacture of plastics mustard gas etc.
4. Ethene gas is used for artificial ripening of raw fruit.
Read more: Ethene C2H4 http://www.friendsmania.net/forum/2nd-year-chemistry-notes/25760.htm#ixzz34b1p0MFH
Ethane C2H6
Introduction
Organic compounds which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are fulfilled by hydrogen atoms are called Saturated Hydrocarbon or alkenes.
The second member of alkane family composed of two carbon and six hydrogen atoms and is known as Ethane.
Structure of Ethane
Ethane is a saturated hydrocarbon, which is composed of two carbon and six hydrogen atoms. Its molecular formula is C2H6. The structural formula of ethane shows that each carbon contains three hydrogen and single bond is present between two carbon atoms.
H3C - CH3
Each carbon atom of ethane is Sp3 hyberidized which contains four equivalent partially filled Sp3 hybrid orbitals, these hybrid orbitals are arranged at the four corners of regular tetrahedron (tetra hedral structure) with an angle of 109.5º.
Three Sp3 hybrid orbitals of carbon atoms overlap with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp3 - S orbitals. The remaining Sp3 hybrid of each carbon atom overlapp with the Sp3 hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp3 - Sp3
Diagram Coming Soon
Preparation of Ethane
Ethane can be prepared by the following methods.
1. From Ethyl Magnesium Iodide
In presence of dry ether when alkyl halide reacts with magnesium metal then Alkyl Magnesium halide is formed. This compound was first synthesized by a German Chemist Grignard, therefore, it is also known as Grignard's Reagent.
2. From Reduction of Ethyl Iodide
When Zn - Cu couple reacts with ethanol then nascent Hydrogen is obtained.
Zn - Cu + 2C2H5OH ----> (C2H5O)2Zn + Cu + 2[H]
Nascent Hydrogen acts as strong reducing agent. When methyl iodide is reduced with nascent hydrogen then methane is formed.
C2H5l + 2[H] ----> C2H6 - Hl
3. From Hydrogenation of Ethane
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst Nickle, Palladium, when ethen is heated with hydrogen at about 250ºC then hydrogenation takes place as a result ethane is obtained.
C2H4 + H2 ----> C2H6
4. By Wurtz Synthesis
When methyl iodide is treated with dry sodium metal, then ethane is formed, in this reaction other products are also formed.
2CH3I + 2Na ----> C2H6 + 2NaI
Physical Properties of Ethane
1. At ordinary temperature and pressure ethane act as colourless gas.
2. Ethane gas is sparingly soluble in water but easily soluble in organic solvents.
3. Ethane gas is lighter then air.
4. The melting point, boiling point and specific gravity of ethane is greater than methane.
Chemical Properties of Ethane
Reactivity
Ethane is a saturated hydrocarbon, which is composed of two carbon and six hydrogen atoms. Its molecular formula is C2H6. The structural formula shows that all the valencies of carbon atoms are fulfilled by hydrogen atoms and single bond is present between two carbon atoms. Therefore, ethane is chemically unreactive. It does not react with any acid, base or oxidizing agents such as KMnO4 or K2Cr2O7. Under special circumstances ethane shows only substitution reaction.
Some important reactions of ethane are given below.
1. Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight when ethane reacts with chlorine (halogen) then chlorination (halogenation) takes place. As a result hydrogen atom of ethane is replaced by chlorine atom to form a substituted product, mono chloro ethane or ethyl chloride.
C2H6 + Cl2 ----> C2H5Cl + HCl
In presence of sunlight and excess chlorine further substitution takes place till all the hydrogen atoms are replaced by chlorine atom.
2. Combustion
When ethane is heated in presence of air or oxygen then carbondioxide and water are formed with the evolution of large amount of heat energy.
C2H6 + 5/2O2 ----> 2CO2 + 3H2O
Uses Of Ethane
Methane is used as fuel.
Read more: Ethane C2H6 http://www.friendsmania.net/forum/2nd-year-chemistry-notes/25759.htm#ixzz34b1uvNV0
Introduction
Organic compounds which are composed, of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are fulfilled by hydrogen atoms are called Saturated Hydrocarbon or alkenes.
The second member of alkane family composed of two carbon and six hydrogen atoms and is known as Ethane.
Structure of Ethane
Ethane is a saturated hydrocarbon, which is composed of two carbon and six hydrogen atoms. Its molecular formula is C2H6. The structural formula of ethane shows that each carbon contains three hydrogen and single bond is present between two carbon atoms.
H3C - CH3
Each carbon atom of ethane is Sp3 hyberidized which contains four equivalent partially filled Sp3 hybrid orbitals, these hybrid orbitals are arranged at the four corners of regular tetrahedron (tetra hedral structure) with an angle of 109.5º.
Three Sp3 hybrid orbitals of carbon atoms overlap with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp3 - S orbitals. The remaining Sp3 hybrid of each carbon atom overlapp with the Sp3 hybrid orbital of other carbon atom to form sigma bond between C - C due to the overlapping of Sp3 - Sp3
Diagram Coming Soon
Preparation of Ethane
Ethane can be prepared by the following methods.
1. From Ethyl Magnesium Iodide
In presence of dry ether when alkyl halide reacts with magnesium metal then Alkyl Magnesium halide is formed. This compound was first synthesized by a German Chemist Grignard, therefore, it is also known as Grignard's Reagent.
2. From Reduction of Ethyl Iodide
When Zn - Cu couple reacts with ethanol then nascent Hydrogen is obtained.
Zn - Cu + 2C2H5OH ----> (C2H5O)2Zn + Cu + 2[H]
Nascent Hydrogen acts as strong reducing agent. When methyl iodide is reduced with nascent hydrogen then methane is formed.
C2H5l + 2[H] ----> C2H6 - Hl
3. From Hydrogenation of Ethane
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst Nickle, Palladium, when ethen is heated with hydrogen at about 250ºC then hydrogenation takes place as a result ethane is obtained.
C2H4 + H2 ----> C2H6
4. By Wurtz Synthesis
When methyl iodide is treated with dry sodium metal, then ethane is formed, in this reaction other products are also formed.
2CH3I + 2Na ----> C2H6 + 2NaI
Physical Properties of Ethane
1. At ordinary temperature and pressure ethane act as colourless gas.
2. Ethane gas is sparingly soluble in water but easily soluble in organic solvents.
3. Ethane gas is lighter then air.
4. The melting point, boiling point and specific gravity of ethane is greater than methane.
Chemical Properties of Ethane
Reactivity
Ethane is a saturated hydrocarbon, which is composed of two carbon and six hydrogen atoms. Its molecular formula is C2H6. The structural formula shows that all the valencies of carbon atoms are fulfilled by hydrogen atoms and single bond is present between two carbon atoms. Therefore, ethane is chemically unreactive. It does not react with any acid, base or oxidizing agents such as KMnO4 or K2Cr2O7. Under special circumstances ethane shows only substitution reaction.
Some important reactions of ethane are given below.
1. Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight when ethane reacts with chlorine (halogen) then chlorination (halogenation) takes place. As a result hydrogen atom of ethane is replaced by chlorine atom to form a substituted product, mono chloro ethane or ethyl chloride.
C2H6 + Cl2 ----> C2H5Cl + HCl
In presence of sunlight and excess chlorine further substitution takes place till all the hydrogen atoms are replaced by chlorine atom.
2. Combustion
When ethane is heated in presence of air or oxygen then carbondioxide and water are formed with the evolution of large amount of heat energy.
C2H6 + 5/2O2 ----> 2CO2 + 3H2O
Uses Of Ethane
Methane is used as fuel.
Read more: Ethane C2H6 http://www.friendsmania.net/forum/2nd-year-chemistry-notes/25759.htm#ixzz34b1uvNV0
Methane CH4
Introduction
Organic compounds, which are composed of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are fulfilled by hydrogen atoms are called Saturated Hydrocarbon or alkanes. The first member of alkane family composed of one carbon and four hydrogen atoms and is known as Methane.
Structure of Methane
Methane is a saturated hydrocarbon, which is composed of one carbon and four hydrogen atoms. Its molecular formula is CH4. The structural formula of methane shows that all the valencies of carbon atoms are fulfilled by hydrogen atoms.
The carbon atoms of methane is Sp3 hyberidized which contains four equivalent partially filled Sp3 hybrid orbitals, these bybrid orbitals are arranged at the four corners of regular tetrahedron (tetra hedral structure) with an angle of 109.5º.
The Sp3 hybrid orbitals 1 of carbon atoms overlapp with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp3 - S orbitals
Preparation of Methane
Methane can be prepared by the following methods.
1. From Sodium Acetate
When concentrated solution of NaOH reacts with acetic acid then sodium acetate is formed.
CH3COOH + NaOH ----> CH3COONa + H2O
When anhydrous sodium acetate reacts with NaOH then methane is obtained.
CH3OONa + NaOH ----> CH4 + Na2CO3
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2. From Methyl Magnesium Iodide
In presence of dry ether when alkyl halide reacts with magnesium metal the Alkyl Magnesium halide is formed. This compound was first synthesized by a German Chemist Grignar, therefore, it is also known as Grignard's Reagent.
3. From Reduction of Methyl Iodide
Methyl iodide can be reduced to methane by the following methods.
a) By Nascent Hydrogen
When concentrated HCl reacts with powdered zinc metal then nascent Hydrogen is obtained.
2HCl + Zn ----> ZnCl2 + 2[H]
Nascent Hydrogen acts as strong reducing agent. When methyl iodide is reduced with nascent hydrogen then methane is formed.
b) By Catalytic Reduction of Methyl Iodide
In presence of catalyst Palladium (Pd), when methyl iodide reacts with hydrogen then methane is formed
Physical Properties of Methane
1. At ordinary temperature and pressure methane exist as colourless, odourless, non-poisonous gas.
2. Methane gas is less soluble in H2O but easily in organic solvents.
3. Methane molecule is non-polar and symmetric.
4. Methane gas is lighter than air.
Chemical Properties of Methane
Reactivity
Methane is a saturated hydrocarbon which is composed of one carbon and four hydrogen atoms. Its molecular formula is CH4. The structural formula shows that all the valencies of carbon atom are fulfilled by Hydrogen atoms. Therefore, at ordinary temperature and pressure, methane is chemically unreactive. It does not react with any acid, base or oxidizing agent such as KMnO4 or K2Cr2 O7. Under special circumstances methane shows substitution reaction.
Those reactions in which any atoms or molecule is replaced by other atom or molecule is called substitution reaction.
Some important chemical reaction of methane are given below.
1. Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight, when chlorine (halogen) reacts with methane then chlorination (halogenation) takes place as a result hydrogen atom of methane is replaced by chlorine atom to form substituted product monochloro methane or methyl chloride is formed.
CH4 + Cl2 ----> CH3Cl + HCl
In presence of sunlight and excess chlorine further substitution takes place till hydrogen atoms are replaced by chlorine atoms.
CH3Cl + Cl2 ----> CH2Cl2 + HCl
CH2Cl2 + Cl2 ----> CHCl3 + HCl
CHCl3 + Cl2 ----> CCl4 + HCl
Mechanism
The mechanism of chlorination (halogenation) in methane proceeds through the following steps.
First Step
In presence of sunlight chlorine molecule dissociate into two chlorine free radicals.
Second Step
Chlorine fee radical combines with methane molecule to form HCl and methyl free radical.
Third Step
Methyl free radical combines with other chlorine molecule to form a substituted product methyl chloride or monochloro methane and chlorine free radical.
2. Combustion
When methane is heated in presence of air and oxygen then carbondioxide and water are formed with the evolution of large amount of heat energy.
CH4 + 2O2 ----> CO2 + 2H2O -ΔH
3. Cracking Or Pyrolysis
The phenomenon in which large molecules are broken into smaller and simple molecule is called Pyrolysis. When Methane is heated in absence of air or oxygen at about 600ºC then Pyrolysis takes place. As a result carbon black and Hydrogen are formed.
Uses of Methane
1. Methane gas is used as domestic fuel.
2. Methane gas is used in manufacture of methanol, carbon black and polishes etc.
Introduction
Organic compounds, which are composed of only carbon and hydrogen atoms are known as hydrocarbons. Those hydrocarbons in which all the valencies of carbon atom are fulfilled by hydrogen atoms are called Saturated Hydrocarbon or alkanes. The first member of alkane family composed of one carbon and four hydrogen atoms and is known as Methane.
Structure of Methane
Methane is a saturated hydrocarbon, which is composed of one carbon and four hydrogen atoms. Its molecular formula is CH4. The structural formula of methane shows that all the valencies of carbon atoms are fulfilled by hydrogen atoms.
The carbon atoms of methane is Sp3 hyberidized which contains four equivalent partially filled Sp3 hybrid orbitals, these bybrid orbitals are arranged at the four corners of regular tetrahedron (tetra hedral structure) with an angle of 109.5º.
The Sp3 hybrid orbitals 1 of carbon atoms overlapp with s atomic orbitals of hydrogen atoms to form a sigma bond between C - H due to the overlapping of Sp3 - S orbitals
Preparation of Methane
Methane can be prepared by the following methods.
1. From Sodium Acetate
When concentrated solution of NaOH reacts with acetic acid then sodium acetate is formed.
CH3COOH + NaOH ----> CH3COONa + H2O
When anhydrous sodium acetate reacts with NaOH then methane is obtained.
CH3OONa + NaOH ----> CH4 + Na2CO3
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2. From Methyl Magnesium Iodide
In presence of dry ether when alkyl halide reacts with magnesium metal the Alkyl Magnesium halide is formed. This compound was first synthesized by a German Chemist Grignar, therefore, it is also known as Grignard's Reagent.
3. From Reduction of Methyl Iodide
Methyl iodide can be reduced to methane by the following methods.
a) By Nascent Hydrogen
When concentrated HCl reacts with powdered zinc metal then nascent Hydrogen is obtained.
2HCl + Zn ----> ZnCl2 + 2[H]
Nascent Hydrogen acts as strong reducing agent. When methyl iodide is reduced with nascent hydrogen then methane is formed.
b) By Catalytic Reduction of Methyl Iodide
In presence of catalyst Palladium (Pd), when methyl iodide reacts with hydrogen then methane is formed
Physical Properties of Methane
1. At ordinary temperature and pressure methane exist as colourless, odourless, non-poisonous gas.
2. Methane gas is less soluble in H2O but easily in organic solvents.
3. Methane molecule is non-polar and symmetric.
4. Methane gas is lighter than air.
Chemical Properties of Methane
Reactivity
Methane is a saturated hydrocarbon which is composed of one carbon and four hydrogen atoms. Its molecular formula is CH4. The structural formula shows that all the valencies of carbon atom are fulfilled by Hydrogen atoms. Therefore, at ordinary temperature and pressure, methane is chemically unreactive. It does not react with any acid, base or oxidizing agent such as KMnO4 or K2Cr2 O7. Under special circumstances methane shows substitution reaction.
Those reactions in which any atoms or molecule is replaced by other atom or molecule is called substitution reaction.
Some important chemical reaction of methane are given below.
1. Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight, when chlorine (halogen) reacts with methane then chlorination (halogenation) takes place as a result hydrogen atom of methane is replaced by chlorine atom to form substituted product monochloro methane or methyl chloride is formed.
CH4 + Cl2 ----> CH3Cl + HCl
In presence of sunlight and excess chlorine further substitution takes place till hydrogen atoms are replaced by chlorine atoms.
CH3Cl + Cl2 ----> CH2Cl2 + HCl
CH2Cl2 + Cl2 ----> CHCl3 + HCl
CHCl3 + Cl2 ----> CCl4 + HCl
Mechanism
The mechanism of chlorination (halogenation) in methane proceeds through the following steps.
First Step
In presence of sunlight chlorine molecule dissociate into two chlorine free radicals.
Second Step
Chlorine fee radical combines with methane molecule to form HCl and methyl free radical.
Third Step
Methyl free radical combines with other chlorine molecule to form a substituted product methyl chloride or monochloro methane and chlorine free radical.
2. Combustion
When methane is heated in presence of air and oxygen then carbondioxide and water are formed with the evolution of large amount of heat energy.
CH4 + 2O2 ----> CO2 + 2H2O -ΔH
3. Cracking Or Pyrolysis
The phenomenon in which large molecules are broken into smaller and simple molecule is called Pyrolysis. When Methane is heated in absence of air or oxygen at about 600ºC then Pyrolysis takes place. As a result carbon black and Hydrogen are formed.
Uses of Methane
1. Methane gas is used as domestic fuel.
2. Methane gas is used in manufacture of methanol, carbon black and polishes etc.
Benzene C6H6
Introduction
Benzene is the basic unit of acromatic hydrocarbon, which is composed of six carbons and six hydrogen atoms. It molecular formula is C6H6. The structural formula of banzene shows that each carbon contains one hydrogen atom and two carbon atoms and alternate single and double bond is present between carbon atoms is a ring.
Diagram Coming Soon
Behaviour of Benzene
The chemical analysis and molecular mass determination shows that the molecular formula of benzene is C6H6, which corresponds to alkane (n-hexane) having a molecular formula C6H14. When benzene is treated with chlorine in dark or with KMnO4 solution, no reaction occurs. When the benzene reacts with nitric acid, chlorine and methyl chloride under different conditions then it shows substitution reaction, that is the characteristic property of hydrocarbon.
When benzene reacts with chlorine in presence of sunlight or with Hydrogen in presence of catalyst then addition reaction takes place, that is the characteristics property of unsaturated hydrocarbon.
Benzene As Unsaturated Hydrocarbon
The characteristic reaction of unsaturated hydrocarbon are addition reactions. The following chemical reactions shows the benzene behaves as unsaturated hydrocarbon. In presence of catalyst Nickle when benzene is heated at 150ºC under 10 atm pressure then hydrogenation takes place as a result cyclohexane is formed
Diagram Coming Soon
In presence of sunlight when benzene reacts with chlorine at 50ºC under 400 atm pressure then chlorination takes place as a result, hexa cyclo hexane is formed.
Diagram Coming Soon
Benzene As Saturated Hydrocarbon
The characteristic reactions of saturated hydrocarbon are substitution reaction. Benzene reacts with different reagents under different conditions and under goes substitution reaction. These reactions show that benzene behaves like a saturated hydrocarbon.
In presence of catalyst concentrated sulphuric acid, when benzene reacts with fuming nitric acid then nitration takes place as a result a substituted product nitro benzene is formed.
Diagram Coming Soon
In presence of catalyst Ferric Chloride (FeCl3) when benzene reacts with chlorine then chlorination takes place as a result a substituted product benzene is formed
Diagram Coming Soon
In presence of catalyst FeCl3, when benzene reacts with methyl chloride the alkylation takes place as a result methyl benzene or Toluene is formed.
Diagram Coming Soon
The above mentioned chemical reaction shows that benzene behaves as a saturated hydrocarbon in spite of a fact that is highly unsaturated hydrocarbon.
Special Character of Benzene
Benzene is not affected by common oxidizing agent such as KMn04 or K2Cr207. Similarly when benzene is treated with chlorine or bromine in dark or with dilute acids no reaction occurs.
However, benzene can easily by oxidized in presence of catalyst Vanadium Pentaoxide (V2O5) to form malcic annydride.
Diagram Coming Soon
Structure of Benzene
Benzene is a basic unit of aeromatic cyclic hydrocarbon which is composed of six carbon and six hydrogen atoms. It molecular formula is C6H6. The structural formula shows that each carbon atom is bonded with one hydrogen atom and two carbon atoms, therefore one free electron is present on each carbon atom which is responsible for the aeromatic character and unusual behaviour of benzene.
Diagram Coming Soon
Different scientists explain the unusual behaviour of benzene and proposed several structures, the detail of which is given below.
1. Kekul Structure
In 1865, Kekul proposed the structure of benzene in which six carbon atoms bonded together by an alternate C - C double bond to form a ring structure. This structural formula suggest the addition reaction should perform by benzene. The resonating structure of benzene is equally represented as under:
Diagram Coming Soon
The above are equivalent and can result by shifting of double bond, which shows that the position of double bond in benzene ring is not fixed so that all C - H position have a partial double bond character.
2. Dewar Structure
Dewar proposed a structure of benzene in which six carbon atoms are bonded together to form hexagonal planer ring in which each carbon attached with one hydrogen and two carbon atoms combined together to form a pi bond as a result the following three resonating structures are formed..
Diagram Coming Soon
3. Armstrong - Bayer Structure
In 1887 Armstrong and in 1892 Bayer proposed Armstrong - Bayer centric formula in which the fourth valency or free electron of each carbon atom is directed towards the center of the molecule, as a result centric density is increased.
Modern Concept of Structure of Benzene
The modern concept of structure of benzene can be explained by the help of following two methods:
1. Atomic Orbital Treatment
2. Rasonance
1. Atomic Orbital Treatment
Benzene is a cyclic hydrocarbon, which is composed of six carbon and six hydrogen atoms, each carbon atom is bonded with one hydrogen and two carbon atoms.
Each carbon atom of benzene is Sp2 hyberdized which contain three equivalent partially fill Sp2 hydrid orbitals and one unhyberdized Pz orbital. The Sp2 bybrid orbitals of each carbon atom are arranged at three corners of triangular planer structure. With an angle of 120ºC.
One Sp2 hybrid orbital of each carbon atom overlapped with S atomic orbital of Hydrogen atom to form a sigma bond between C - H due to the overlapping of Sp2 - S orbitals. The remaining two Sp2 hybrid orbitals of each carbon atom overlapped with Sp2 bybrid of two different carbon atoms to form sigma bond between adjacent C - C due to the linearly overlapping of Sp2 - Sp2 orbital.
Diagram Coming Soon
The unhyberdized Pz orbital of each carbon atom is situated perpendicular to the Sp2 plane and parallel to the unhyberidized Pz orbital of other carbon atom. The unhyberdized Pz orbital of two adjacent carbon atoms overlap side by side to form a pi bond between two carbon atoms, therefore three alternate double bonds are formed between carbon atoms in a ring.
Diagram Coming Soon
Since the C - C bond lengths in benzene are same i.e. 1.39 Aº, each orbital overlaps with its neighbour equally, therefore all six Pz orbitals overlapped with each other to form a single molecular orbital in such a way an electronic cloud is formed above and below the Sp2 plane (benzene ring) and atrons in benzene is not fixed or they are de localized.
Diagram Coming Soon
2. Resonance Or Modern Representation of Structure of Benzene.
Definition
The phenomenon in which position of double bond or pi electroni
1. From Saturated Hydrocarbon
The following two methods show the preparation of benzene from saturated hydrocarbon.
A. From Petroleum or n - Hexane
When n-hexane is heated about 480ºC - 550ºC under 150psi - 300psi pressure and in presence of catalyst such as V2O5 then cyclization takes place as a result cyclo hexame is formed which on dehydrogenation convert into benzene.
Diagram Coming Soon
B. From n - Heptane
It presence of catalyst when n-heptane is heated temperature under high pressure then Toluene is formed, which on heating 500ºC - 760ºC in presence of catalyst Co - Mo convert into benzene.
Diagram Coming Soon
2. From Unsaturated Hydrocarbon
It presence of catalyst organonickle when ethyne or acetylene is passed throuigh red hot tube then polymerization takes place as a result benzene is formed
Diagram Coming Soon
3. From Phenol
When the vapours of Phenol are passed over red-hot zinc dust, then reduction takes place, as a result benzene is formed.
C6H5OH + Zn + C6H6 + ZnO
4. From Sodium Benzene
When sodium benzoate is heated with sodium hydroxide then benzene is formed.
Diagram Coming Soon
Reaction of Benzene or Chemical Properties of Benzene
Substitution Reaction of Benzene
Those atoms or molecules or ions, which are electron deficient or contains positive charge are known as electrophile. The chemical reactions in which one electrophile is replaced by another electrophile are called Electrophile Substitution Reaction.
The structure of benzene shows that there is a cloud of pi electrons above and below the plane of benzene molecule. These pi electrons (Ï€) are responsible for electrophile substitution reaction of benzene.
In benzene hydrogen atom act as electrophile. Therefore when any electrophillic reagent reacts with benzene then the hydrogen atom is replaced by attacking molecule to form substituted benzene.
Diagram Coming Soon
General Mechanism of Electrophilic Substitution Reactions of Benzene.
The electrophilic substitution reaction in benzene occurs through following mechanism. The π electron which are spread above and below the plane of benzene molecule are responsible for this reaction. An electrophile attacks the pi system of benzene to form a delocalized carbonium ion or sigma complex. The electrophile does this by taking two electrons of Pz orbital to form a sigma bond between it and one carbon atom of benzene ring. This breaks the cyclic system of pi electrons because one carbon becomes Sp3 hyberidized.
This causes instability to the ring, to overcome this instability the benzonium loses a proton from the carbon that bears the electrophile. The loss of proton result in the regeneration of the double bond, which restores the stability of ring and formation of, substituted product.
Diagram Coming Soon
Some important electophillic substitution reaction of benzene are given below.
a) Nitration
Introduction of nitro group (NO2)in a compound is called nitration. When benzene reacts with a 1:1 mixture of concentrated nitric acid and concentrated sulphuric acid then nitration takes place as a result nito benzene is formed. In this reaction H2SO4 act as a catalyst.
Diagram Coming Soon
b)Sulphonation
Introduction of sulphonic group (HSO3) in a compound is called sulphonation. When benzene reacts with fuming H2SO4 i.e. H2SO4 saturated with SO3, at room temperature then sulphonation takes place as a result benzene sulphonic is formed.
Diagram Coming Soon
Various steps of mechanism of sulphonation of benzene are given bwlow
H+HSO4- + SO3 ----> HSO3+ + HSO4-
Diagram Coming Soon
c) Halogenation
Introduction of halogen in a compound is called halogenation. In presence of Lewis acid catalyst FeX3, or AlX3, when benzene reacts with halogen than halogenation takes place. As a result halobenzene is formed
Diagram Coming Soon
d) Alkylation
Introduction of Alkyle group R in a compound is called alkylation. In presence of catalyst FeX3 or AlX3, when benzene reacts reacts with alkyl halide then alkylation takes place. As result alkyle benzene is formed
Diagram Coming Soon
Various steps of mechanism of alkylation are given below.
R+X + FeX3 ----> R+ + FeX4-
Diagram Coming Soon
e) Acylation
Introduction of acyl group (R - C = 0) in a compound is called acylation. In presence of catalyst FeX3 or AlX3 when benzene reacts with acyl halide then acylation takes place. As a result, acyl benzene is formed.
Various steps of mechanism of acylation are given below.
Diagram Coming Soon
f) Friedal and Crafts Reaction
General chemist friedal and crafts first introduced alkyl group and acyle group in benzene in presence of catalyst FeX3 or AlX3, Therefore, the alkylation and acylation reaction are collectively known as Friedal and Crafts reactions.
2. Addition Reaction of Benzene
Under general circumstances, Benzene under goes addition reaction. As a result of these reactions, the aeromatic character of ring is lost and benzene is reduced to saturated cyclic compound.
Some important addition reactions of benzene are
a) Hydrogenation
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst nickle. When benzene is heated at about 150ºC under 10 atm pressure, then hydrogenation takes place. As a result cyclo hexane is formed
C6H6 - 3H2 ----> C6H12 (150ºC, 10 atm, Ni)
b) Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight, when benzene is heated with chlorine at about 50ºC under 400 atm pressure, then halogenation (chlorination) takes place. As a result hexa chloro cyclo hexane is formed.
Diagram Coming Soon
3. Oxidation
Benzene do not oxidize by common oxidizing agents such as aqueous alkaline solution of KmnO4 or acidic solution of K2Cr2O7. But in pressure of catalyst Vanadium Pentaoxide (V2O5) benzene is oxidized by oxygen to form a Maleic anhydride.
Diagram Coming Soon
Orientation In Benzene
Introduction
Benzene is a basic unit of aeromatic hydrocarbon, which is composed of six carbons and six hydrogen atoms. It molecular formula is C6H6. The structural formula of benzene shows that each carbon contains one hydrogen atom and two carbon atoms and alternate single and double is present between carbon atoms is a ring. Therefore, all carbons atoms and Hydrogen atoms of benzene ring are identical.
Diagram Coming Soon
Explanation
Benzene shows an electrophillic substitution reaction in which one hydrogen atom of benzene is replaced by attacking electrophile E+ as a result, a stable substituted benzene is formed.
C6H6 + E+ ----> C6H5E + H+
In substituted benzene all carbon atoms are not equivalent, therefore the carbon number 1 and 4 are called Para Positions, carbon number 2 and 6 are called Ortho Positions and carbon number 3 and 5 are called Meta Positions.
Diagram Coming Soon
1, 4 - Para Positions
2, 6 - Ortho Position
3, 5 - Meta Position
In presence of first substituent E+ the incoming second electrophile Y+ may occupie any of Orth, Para or Meta Position.
Classification of First Substituent Group
Since the incoming second electrophile i.e. Y+ occupie the position as it given by the first electrophile E+. Therefore the first substituent group E+ can be classified into two main groups according to their influence on the reactivity of the ring.
1. Meta Directing Group
2. Ortho Directing Group
1. Meta Directing Group
NO2, HSO3, COOH, COOR, CHO, COR, .... are meta directing group, because they orient or direct the incoming second substituent group Y+ to Meta Position.
Examples
a). Chlorination of Nitro Benzene
In presence of catalyst, FeCl3 when nitro benzene reacts with chlorine then chlorination takes place as a result first Meta chloro nitro benzene and meta dichloro nitro benzene are formed.
C6H5NO2 + Cl2 ----> C6H4NO2Cl + HCl
C6H5NO2 + Cl2 ----> C6H4NO2Cl2 + HCl
b). In presence of catalyst concentrated sulphuric acid, when nitro benzene is heated with nitric acid then nitration takes place, as a result Meta trinitro benzene is formed
C6H5NO2 + NO2OH ----> C6H4(NO2)2 + H2O
C6H4(NO2)2 + NO2OH ----> C6H3(NO2)3 + H2O
c). Nitration of Benzoic Acid
In presence of catalyst concentrated sulphuric acid when benzoic reacts with fuming nitric acid (HNO3), then nitration takes place as a result meta di nitro benzoic acid is formed.
C6H5COOH + NO2OH ----> C6H4NO2COOH + H2O
C6H4NO2COOH + NO2OH ----> C6H3(NO2)2COOH + H2O
2. Ortho Directing Group
X, R, OH, NH2, NR2, NHCOR ... are ortho para directing group, because they orient or direct the incoming second substituent group Y+ to ortho para position. As a result a mixture of ortho and para substituted product is formed.
Examples
a). Nitration of Chloro Benzene
In presence of catalyst, concentrated sulphuric acid when chloro benzene reacts with Nitric Acid then Nitration takes place as a result a mixture of ortho nitro chloro benzene and para nitro chloro benzene is formed.
C6H5Cl + NO2OH ----> C6H4CINO2
b). Nitration of Methyl Benzene
In presence of catalyst concentrated sulphuric acid, when methyl benzene or Toluene reacts with nitric acid then nitration takes place, as a result a mixture of ortho nitro toluene and para nitro toluene are formed
C6H5CH3 + NO2OH ----> C6H4CH3NO2
Introduction
Benzene is the basic unit of acromatic hydrocarbon, which is composed of six carbons and six hydrogen atoms. It molecular formula is C6H6. The structural formula of banzene shows that each carbon contains one hydrogen atom and two carbon atoms and alternate single and double bond is present between carbon atoms is a ring.
Diagram Coming Soon
Behaviour of Benzene
The chemical analysis and molecular mass determination shows that the molecular formula of benzene is C6H6, which corresponds to alkane (n-hexane) having a molecular formula C6H14. When benzene is treated with chlorine in dark or with KMnO4 solution, no reaction occurs. When the benzene reacts with nitric acid, chlorine and methyl chloride under different conditions then it shows substitution reaction, that is the characteristic property of hydrocarbon.
When benzene reacts with chlorine in presence of sunlight or with Hydrogen in presence of catalyst then addition reaction takes place, that is the characteristics property of unsaturated hydrocarbon.
Benzene As Unsaturated Hydrocarbon
The characteristic reaction of unsaturated hydrocarbon are addition reactions. The following chemical reactions shows the benzene behaves as unsaturated hydrocarbon. In presence of catalyst Nickle when benzene is heated at 150ºC under 10 atm pressure then hydrogenation takes place as a result cyclohexane is formed
Diagram Coming Soon
In presence of sunlight when benzene reacts with chlorine at 50ºC under 400 atm pressure then chlorination takes place as a result, hexa cyclo hexane is formed.
Diagram Coming Soon
Benzene As Saturated Hydrocarbon
The characteristic reactions of saturated hydrocarbon are substitution reaction. Benzene reacts with different reagents under different conditions and under goes substitution reaction. These reactions show that benzene behaves like a saturated hydrocarbon.
In presence of catalyst concentrated sulphuric acid, when benzene reacts with fuming nitric acid then nitration takes place as a result a substituted product nitro benzene is formed.
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In presence of catalyst Ferric Chloride (FeCl3) when benzene reacts with chlorine then chlorination takes place as a result a substituted product benzene is formed
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In presence of catalyst FeCl3, when benzene reacts with methyl chloride the alkylation takes place as a result methyl benzene or Toluene is formed.
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The above mentioned chemical reaction shows that benzene behaves as a saturated hydrocarbon in spite of a fact that is highly unsaturated hydrocarbon.
Special Character of Benzene
Benzene is not affected by common oxidizing agent such as KMn04 or K2Cr207. Similarly when benzene is treated with chlorine or bromine in dark or with dilute acids no reaction occurs.
However, benzene can easily by oxidized in presence of catalyst Vanadium Pentaoxide (V2O5) to form malcic annydride.
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Structure of Benzene
Benzene is a basic unit of aeromatic cyclic hydrocarbon which is composed of six carbon and six hydrogen atoms. It molecular formula is C6H6. The structural formula shows that each carbon atom is bonded with one hydrogen atom and two carbon atoms, therefore one free electron is present on each carbon atom which is responsible for the aeromatic character and unusual behaviour of benzene.
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Different scientists explain the unusual behaviour of benzene and proposed several structures, the detail of which is given below.
1. Kekul Structure
In 1865, Kekul proposed the structure of benzene in which six carbon atoms bonded together by an alternate C - C double bond to form a ring structure. This structural formula suggest the addition reaction should perform by benzene. The resonating structure of benzene is equally represented as under:
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The above are equivalent and can result by shifting of double bond, which shows that the position of double bond in benzene ring is not fixed so that all C - H position have a partial double bond character.
2. Dewar Structure
Dewar proposed a structure of benzene in which six carbon atoms are bonded together to form hexagonal planer ring in which each carbon attached with one hydrogen and two carbon atoms combined together to form a pi bond as a result the following three resonating structures are formed..
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3. Armstrong - Bayer Structure
In 1887 Armstrong and in 1892 Bayer proposed Armstrong - Bayer centric formula in which the fourth valency or free electron of each carbon atom is directed towards the center of the molecule, as a result centric density is increased.
Modern Concept of Structure of Benzene
The modern concept of structure of benzene can be explained by the help of following two methods:
1. Atomic Orbital Treatment
2. Rasonance
1. Atomic Orbital Treatment
Benzene is a cyclic hydrocarbon, which is composed of six carbon and six hydrogen atoms, each carbon atom is bonded with one hydrogen and two carbon atoms.
Each carbon atom of benzene is Sp2 hyberdized which contain three equivalent partially fill Sp2 hydrid orbitals and one unhyberdized Pz orbital. The Sp2 bybrid orbitals of each carbon atom are arranged at three corners of triangular planer structure. With an angle of 120ºC.
One Sp2 hybrid orbital of each carbon atom overlapped with S atomic orbital of Hydrogen atom to form a sigma bond between C - H due to the overlapping of Sp2 - S orbitals. The remaining two Sp2 hybrid orbitals of each carbon atom overlapped with Sp2 bybrid of two different carbon atoms to form sigma bond between adjacent C - C due to the linearly overlapping of Sp2 - Sp2 orbital.
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The unhyberdized Pz orbital of each carbon atom is situated perpendicular to the Sp2 plane and parallel to the unhyberidized Pz orbital of other carbon atom. The unhyberdized Pz orbital of two adjacent carbon atoms overlap side by side to form a pi bond between two carbon atoms, therefore three alternate double bonds are formed between carbon atoms in a ring.
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Since the C - C bond lengths in benzene are same i.e. 1.39 Aº, each orbital overlaps with its neighbour equally, therefore all six Pz orbitals overlapped with each other to form a single molecular orbital in such a way an electronic cloud is formed above and below the Sp2 plane (benzene ring) and atrons in benzene is not fixed or they are de localized.
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2. Resonance Or Modern Representation of Structure of Benzene.
Definition
The phenomenon in which position of double bond or pi electroni
1. From Saturated Hydrocarbon
The following two methods show the preparation of benzene from saturated hydrocarbon.
A. From Petroleum or n - Hexane
When n-hexane is heated about 480ºC - 550ºC under 150psi - 300psi pressure and in presence of catalyst such as V2O5 then cyclization takes place as a result cyclo hexame is formed which on dehydrogenation convert into benzene.
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B. From n - Heptane
It presence of catalyst when n-heptane is heated temperature under high pressure then Toluene is formed, which on heating 500ºC - 760ºC in presence of catalyst Co - Mo convert into benzene.
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2. From Unsaturated Hydrocarbon
It presence of catalyst organonickle when ethyne or acetylene is passed throuigh red hot tube then polymerization takes place as a result benzene is formed
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3. From Phenol
When the vapours of Phenol are passed over red-hot zinc dust, then reduction takes place, as a result benzene is formed.
C6H5OH + Zn + C6H6 + ZnO
4. From Sodium Benzene
When sodium benzoate is heated with sodium hydroxide then benzene is formed.
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Reaction of Benzene or Chemical Properties of Benzene
Substitution Reaction of Benzene
Those atoms or molecules or ions, which are electron deficient or contains positive charge are known as electrophile. The chemical reactions in which one electrophile is replaced by another electrophile are called Electrophile Substitution Reaction.
The structure of benzene shows that there is a cloud of pi electrons above and below the plane of benzene molecule. These pi electrons (Ï€) are responsible for electrophile substitution reaction of benzene.
In benzene hydrogen atom act as electrophile. Therefore when any electrophillic reagent reacts with benzene then the hydrogen atom is replaced by attacking molecule to form substituted benzene.
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General Mechanism of Electrophilic Substitution Reactions of Benzene.
The electrophilic substitution reaction in benzene occurs through following mechanism. The π electron which are spread above and below the plane of benzene molecule are responsible for this reaction. An electrophile attacks the pi system of benzene to form a delocalized carbonium ion or sigma complex. The electrophile does this by taking two electrons of Pz orbital to form a sigma bond between it and one carbon atom of benzene ring. This breaks the cyclic system of pi electrons because one carbon becomes Sp3 hyberidized.
This causes instability to the ring, to overcome this instability the benzonium loses a proton from the carbon that bears the electrophile. The loss of proton result in the regeneration of the double bond, which restores the stability of ring and formation of, substituted product.
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Some important electophillic substitution reaction of benzene are given below.
a) Nitration
Introduction of nitro group (NO2)in a compound is called nitration. When benzene reacts with a 1:1 mixture of concentrated nitric acid and concentrated sulphuric acid then nitration takes place as a result nito benzene is formed. In this reaction H2SO4 act as a catalyst.
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b)Sulphonation
Introduction of sulphonic group (HSO3) in a compound is called sulphonation. When benzene reacts with fuming H2SO4 i.e. H2SO4 saturated with SO3, at room temperature then sulphonation takes place as a result benzene sulphonic is formed.
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Various steps of mechanism of sulphonation of benzene are given bwlow
H+HSO4- + SO3 ----> HSO3+ + HSO4-
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c) Halogenation
Introduction of halogen in a compound is called halogenation. In presence of Lewis acid catalyst FeX3, or AlX3, when benzene reacts with halogen than halogenation takes place. As a result halobenzene is formed
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d) Alkylation
Introduction of Alkyle group R in a compound is called alkylation. In presence of catalyst FeX3 or AlX3, when benzene reacts reacts with alkyl halide then alkylation takes place. As result alkyle benzene is formed
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Various steps of mechanism of alkylation are given below.
R+X + FeX3 ----> R+ + FeX4-
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e) Acylation
Introduction of acyl group (R - C = 0) in a compound is called acylation. In presence of catalyst FeX3 or AlX3 when benzene reacts with acyl halide then acylation takes place. As a result, acyl benzene is formed.
Various steps of mechanism of acylation are given below.
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f) Friedal and Crafts Reaction
General chemist friedal and crafts first introduced alkyl group and acyle group in benzene in presence of catalyst FeX3 or AlX3, Therefore, the alkylation and acylation reaction are collectively known as Friedal and Crafts reactions.
2. Addition Reaction of Benzene
Under general circumstances, Benzene under goes addition reaction. As a result of these reactions, the aeromatic character of ring is lost and benzene is reduced to saturated cyclic compound.
Some important addition reactions of benzene are
a) Hydrogenation
Introduction of hydrogen in a compound is called hydrogenation. In presence of catalyst nickle. When benzene is heated at about 150ºC under 10 atm pressure, then hydrogenation takes place. As a result cyclo hexane is formed
C6H6 - 3H2 ----> C6H12 (150ºC, 10 atm, Ni)
b) Halogenation
Introduction of halogen in a compound is called halogenation. In presence of sunlight, when benzene is heated with chlorine at about 50ºC under 400 atm pressure, then halogenation (chlorination) takes place. As a result hexa chloro cyclo hexane is formed.
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3. Oxidation
Benzene do not oxidize by common oxidizing agents such as aqueous alkaline solution of KmnO4 or acidic solution of K2Cr2O7. But in pressure of catalyst Vanadium Pentaoxide (V2O5) benzene is oxidized by oxygen to form a Maleic anhydride.
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Orientation In Benzene
Introduction
Benzene is a basic unit of aeromatic hydrocarbon, which is composed of six carbons and six hydrogen atoms. It molecular formula is C6H6. The structural formula of benzene shows that each carbon contains one hydrogen atom and two carbon atoms and alternate single and double is present between carbon atoms is a ring. Therefore, all carbons atoms and Hydrogen atoms of benzene ring are identical.
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Explanation
Benzene shows an electrophillic substitution reaction in which one hydrogen atom of benzene is replaced by attacking electrophile E+ as a result, a stable substituted benzene is formed.
C6H6 + E+ ----> C6H5E + H+
In substituted benzene all carbon atoms are not equivalent, therefore the carbon number 1 and 4 are called Para Positions, carbon number 2 and 6 are called Ortho Positions and carbon number 3 and 5 are called Meta Positions.
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1, 4 - Para Positions
2, 6 - Ortho Position
3, 5 - Meta Position
In presence of first substituent E+ the incoming second electrophile Y+ may occupie any of Orth, Para or Meta Position.
Classification of First Substituent Group
Since the incoming second electrophile i.e. Y+ occupie the position as it given by the first electrophile E+. Therefore the first substituent group E+ can be classified into two main groups according to their influence on the reactivity of the ring.
1. Meta Directing Group
2. Ortho Directing Group
1. Meta Directing Group
NO2, HSO3, COOH, COOR, CHO, COR, .... are meta directing group, because they orient or direct the incoming second substituent group Y+ to Meta Position.
Examples
a). Chlorination of Nitro Benzene
In presence of catalyst, FeCl3 when nitro benzene reacts with chlorine then chlorination takes place as a result first Meta chloro nitro benzene and meta dichloro nitro benzene are formed.
C6H5NO2 + Cl2 ----> C6H4NO2Cl + HCl
C6H5NO2 + Cl2 ----> C6H4NO2Cl2 + HCl
b). In presence of catalyst concentrated sulphuric acid, when nitro benzene is heated with nitric acid then nitration takes place, as a result Meta trinitro benzene is formed
C6H5NO2 + NO2OH ----> C6H4(NO2)2 + H2O
C6H4(NO2)2 + NO2OH ----> C6H3(NO2)3 + H2O
c). Nitration of Benzoic Acid
In presence of catalyst concentrated sulphuric acid when benzoic reacts with fuming nitric acid (HNO3), then nitration takes place as a result meta di nitro benzoic acid is formed.
C6H5COOH + NO2OH ----> C6H4NO2COOH + H2O
C6H4NO2COOH + NO2OH ----> C6H3(NO2)2COOH + H2O
2. Ortho Directing Group
X, R, OH, NH2, NR2, NHCOR ... are ortho para directing group, because they orient or direct the incoming second substituent group Y+ to ortho para position. As a result a mixture of ortho and para substituted product is formed.
Examples
a). Nitration of Chloro Benzene
In presence of catalyst, concentrated sulphuric acid when chloro benzene reacts with Nitric Acid then Nitration takes place as a result a mixture of ortho nitro chloro benzene and para nitro chloro benzene is formed.
C6H5Cl + NO2OH ----> C6H4CINO2
b). Nitration of Methyl Benzene
In presence of catalyst concentrated sulphuric acid, when methyl benzene or Toluene reacts with nitric acid then nitration takes place, as a result a mixture of ortho nitro toluene and para nitro toluene are formed
C6H5CH3 + NO2OH ----> C6H4CH3NO2