CHEMISTRY ASSIGNMENT
1. Raoult’s law is a special case of Henry’s law, comment. (1)
2. Why is a solution of ethylene glycol and water used as an antifreeze? (1)
3. Why is a bottle of ammonia cooled before opening the seal? (1)
4. In which of the following solvents will we get an abnormal molar mass for benzonic acid?
i) Water ii) Benzene . Give reason. (1)
5. What is the Van’t Hoff factor for – K4[Fe(CN)6] and K2SO4 (1)
6. Arrange the following one molal aqueous solutions in the increasing order of boiling points and
freezing points – glucose, sodium chloride, sodium phosphate, aluminium phosphate. (1)
7. Define vapour pressure of a liquid. What are the factors which influence the vapour pressure of
the liquid? (2)
8. Give reasons for the following observations: (1)
i) Salt is sprinkled on roads to clear the snow.
ii) A little salt is added to water while boiling eggs to avoid their breaking.
iii) Medicines are dissolved in 0.9% solution of NaCl before giving intravenous injections.
iv) Raw mangoes are placed in concentrated salt solution before making pickle.
v) Wilted flowers can come back to shape if placed in fresh water.
vi) Saline gargles are suggested to soothe sore throat.
9. Explain the cause of non-ideal behaviours shown by a solution of (2)
i) Ethanol and acetone
ii) Acetone and chloroform
10. Boiling point of water increases by addition of common salt while the freezing point is lowered.
Represent this information graphically. (2)
11. Will the elevation in boiling point be same if 0.1 mole of sodium chloride or 0.1 mole
of sugar is dissolved in IL of water? Reason out your answer. (1)
12. Which colligative property is best suited to find the molar mass of a polymer? Give reason.(1)
13. A solution has 1:4 mole ratio for solute and solvent. The vapour pressure of solute and solvent are
440 and 120 mm of mercury respectively. The mole fraction of solute in the vapour phase will be:
a) 0.200 b) 0.549 c) 0.786 d) 0.478. (1)
Q.14 4% NaOH (W/V) and 6% urea solution (W/V) are equimolar but not isotonic. Why? (1)
Q.15 The vapour pressure of water at 25.0° C is 23.8 torr. Determine the mass of sodium chloride
needed to add to 400ml of water to change the vapour pressure to 2.8 torr. Assume the density
of water to be 1.0g/ml. (1)
Q.16 At the same temperature, Hydrogen is more soluble in water than Helium. Which of them
will have a higher value of KH and why? (2)
Q.17 Phenol associates in benzene to a certain extent to form dimer. A solution containing 2 x
10-2 kg of phenol in 1 kg of benzene has its freezing point decreased by 0.69K. Calculate
degree of association of phenol (If Kf for benzene is 5.12°K kg/ mol (3)
Q.18 At a given temperature the vapour pressure of pure liquid diethyl ether & isopropyl alcohol are
730 torr & 310 torr respectively. A solution prepared by mixing isopropyl alcohol & diethyl ether
obeys Raoult’s Law. At this temperature, what is the vapour pressure of diethyl ether over a
solution in which its mole fraction is 0.270? (2)
Q.19 Two sodium chloride solutions are separated by a semi permeable membrane. The concentration
of solution ‘A’ is 0.50 M and the concentration of solution ‘B’ is 0.250 M. Over time, there will
be a measurable movement of (1)
(a) Water from solution A to B. (b) Water from solution B to A.
(c) Sodium chloride from solution B to A (d) Sodium chloride from solution A to B
(e) two of these are correct.
Q.20 On the basis of the given observation in each case predict (a) whether i=1 ,i<1or i>1
(b) comment on the molecular state of the solute whether normal, association or
dissociation.
(i) ∆Tb : expected 0.82 K, observed 0.82 K
(ii) π: expected 1.8 bar , observed 2.1 bar
(iii) ∆Tf: expected 1.68K, observed 1.42 K (3)
Q.21 Of the following compounds, which are likely to increase in solubility as the temperature of the
solution increases?
(a) Glucose, C6H12O6 (b) CO2 (c) NaBr (d) CuSO4 (e) CH4
Q.22 A nurse prepared three injections of concentration 1.0%, 0.75% and 0.9% saline to be injected
intravenously to a patient. Which is the most suitable concentration to be used? Why? (2)
TOPIC: SOLID STATE
1. An alloy of gold and cadmium crystallizes with a cubic structure in which gold atoms occupy the
corners and cadmium atoms fit into face centres. What formula would you assign to the alloy?
2. Diamond and graphite are two different ‘polymorphic’ forms of carbon. What do you understand
by this statement?
3. NaCl and Cu are both conductors of electricity. What do you understand by this statement?
4. On heating crystals of KCl in potassium vapours, the crystal exhibiting a violet colour, why?
5. Explain the following observations:
i) Solids have high density and low compressibility.
ii) Melting point of crystalline solids is sharp whereas that of amorphous solid is not.
iii) Ionic solids have high melting and boiling point.
6. For octahedral coordination, what should be the range of radius ratio r+ / r- value?
7. Thallium chloride, TlCl crystallizes in either a simple cubic lattice or a face centred cubic lattice
of Clions with Tl+
cell is 3.8510-8
8. What is the difference between a tetrahedral void and an octahedral void.
9. Niobium crystallizes in a body centered cubic structure. If density is 8.55g/cm3
atomic radius of niobium, given that its atomic mass is 93u.
ions in the holes. If the density of the solid is 9gm/c.c. and edge of the unit
cm, what is the unit cell geometry?
10. What are 13-15 and 12-16 compound. Explain giving examples.
11. What is an antiferroelectric solid?
12. Classify the following as p-type or n-type semiconductor-
i) Ge doped with In (ii) B doped with Si
13. Iron II oxide has a cubic structure and each unit cell has side 5Å. If the density of the oxide is
4g/cm3
72g mol-1
14. Calculate the efficiency of packing in case of metal crystal for-
i) simple cubic ii) body centred cubic (iii) face centred cubic
15. Gold (at radius =0.144nm) crystallizes in FCC unit cell. What is the length of side of the cell?
16 Analysis shows that nickel oxide has the formula Ni0.98O.What fraction of Ni exist as Ni2+ and
Ni3+ ions?
17. Chromium metal crystallises with BCC lattice. The length of the unit cell edge is found to be 287
pm. Calculate the atomic radius. What would be the density of chromium in g/cm3
18 Differentiate between with diagram
i) Schottky and Frenkel defect. ii) Ferromagnetic and ferrimagnetic substances.
19. What is the total volume of atoms in a face-centred cubic unit cell of a metal with radius ‘r’?
20. In a crystalline solid, anions B are arranged in ccp. cations A are distributed equally between
tetrahedral and octahedral voids. If all the octahedral voids are occupied find formula.
. Calculate the number of Fe2+ and O2-
)
ions present in each unit cell. (Molar Mass of FeO =
1. Unlike phenols ,alcohols are easily protonated. Why?
2. Give chemical tests to distinguish between i) Phenol and Cyclohexanol and ii) Benzyl
alcohol & 2-Propanol, iii) Phenol & Benzoic acid , iv) sec & tert-butanol.
3. Propose a suitable mechanism for the preparation of ethoxyethane from ethanol.
4. Name the reagents which are used in following conversions:
i) 1°alcohol to an aldehyde, ii) butan-2-one to butan-2-ol, iii) phenol to 2,4,6-
tribromophenol.
5 .Why Me3COH is less acidic than Me3COH although carbon is more electronegative than
Si?
6 .Which one is more acidic : phenol or cresol? Why?
7. Predict the major product of acid-catalysed dehydration of : i) 1-methylcyclohexanol and
ii) butanol
8. Ortho and para nitrophenols are more acidic than phenol. Explain this observation with
the help of resonating structures of corresponding phenoxide ions.
9. Phenol is acidic yet it doesn’t react with sodium bicarbonate.Why?
10. Account for the following:
i) Methyl phenyl ether reacts with HI to give phenol & methyl iodide and not iodobenzene
and methyl alcohol.
ii) Order of reactivity of HX towards the cleavage of ethers is: HI>HBr>HCl
iii) Alcohols are freely soluble in water while haloalkanes are not.
iv) Alcohols act as weak bases.
v) Phenol has a smaller dipole moment than methanol.
vi) Acidity of alcohols follows the order: 1°>2°>3°.
vii) Symmetrical ethers also possess a net dipole moment.
viii) Acid catalysed dehydration of t-butanol is faster than n-butanol.
ix) Sodium metal can be used for drying diethyl ether and benzene but not for an alcohol.
11. Describe the following :
i) Kolbe’s reaction
ii) Reamer Tiemann reaction
iii) Coupling reaction
iv) Schotten-Baumann reaction
v) Esterification
vi) Fischer esterification
vii) Williamson’s synthesis
12.What happens when:
i) Ethanoyl chloride is treated with phenol
ii) Phenol is reacted with neutral FeCl3.
iii) Phenetole reacts with HI at 373K
iv) Diethyl ether reacts with Cl2 in dark.
13. The products of the reaction between Ethanol & H2SO4 depend upon the conditions
applied. Justify.
14. Conversions:
i) Benzene to cumene
ii) Phenol to p-hydroxyazobenzene
iii) Methanol to ethanol
iv) Ethanol to sodium ethoxide
v) Chlorobenzene to phenol
vi) Sodium propoxide to propoxypropane
vii) Ethylmagnesiumbromide to 1-propanol
viii) Propanol to 2-methyl-2-propanol
15. Describe the following processes with example:
i) Protonation , ii) acetylation
TOPIC : SOLUTIONS
1. Raoult’s law is a special case of Henry’s law, comment. (1)
2. Why is a solution of ethylene glycol and water used as an antifreeze? (1)
3. Why is a bottle of ammonia cooled before opening the seal? (1)
4. In which of the following solvents will we get an abnormal molar mass for benzonic acid?
i) Water ii) Benzene . Give reason. (1)
5. What is the Van’t Hoff factor for – K4[Fe(CN)6] and K2SO4 (1)
6. Arrange the following one molal aqueous solutions in the increasing order of boiling points and
freezing points – glucose, sodium chloride, sodium phosphate, aluminium phosphate. (1)
7. Define vapour pressure of a liquid. What are the factors which influence the vapour pressure of
the liquid? (2)
8. Give reasons for the following observations: (1)
i) Salt is sprinkled on roads to clear the snow.
ii) A little salt is added to water while boiling eggs to avoid their breaking.
iii) Medicines are dissolved in 0.9% solution of NaCl before giving intravenous injections.
iv) Raw mangoes are placed in concentrated salt solution before making pickle.
v) Wilted flowers can come back to shape if placed in fresh water.
vi) Saline gargles are suggested to soothe sore throat.
9. Explain the cause of non-ideal behaviours shown by a solution of (2)
i) Ethanol and acetone
ii) Acetone and chloroform
10. Boiling point of water increases by addition of common salt while the freezing point is lowered.
Represent this information graphically. (2)
11. Will the elevation in boiling point be same if 0.1 mole of sodium chloride or 0.1 mole
of sugar is dissolved in IL of water? Reason out your answer. (1)
12. Which colligative property is best suited to find the molar mass of a polymer? Give reason.(1)
13. A solution has 1:4 mole ratio for solute and solvent. The vapour pressure of solute and solvent are
440 and 120 mm of mercury respectively. The mole fraction of solute in the vapour phase will be:
a) 0.200 b) 0.549 c) 0.786 d) 0.478. (1)
Q.14 4% NaOH (W/V) and 6% urea solution (W/V) are equimolar but not isotonic. Why? (1)
Q.15 The vapour pressure of water at 25.0° C is 23.8 torr. Determine the mass of sodium chloride
needed to add to 400ml of water to change the vapour pressure to 2.8 torr. Assume the density
of water to be 1.0g/ml. (1)
Q.16 At the same temperature, Hydrogen is more soluble in water than Helium. Which of them
will have a higher value of KH and why? (2)
Q.17 Phenol associates in benzene to a certain extent to form dimer. A solution containing 2 x
10-2 kg of phenol in 1 kg of benzene has its freezing point decreased by 0.69K. Calculate
degree of association of phenol (If Kf for benzene is 5.12°K kg/ mol (3)
Q.18 At a given temperature the vapour pressure of pure liquid diethyl ether & isopropyl alcohol are
730 torr & 310 torr respectively. A solution prepared by mixing isopropyl alcohol & diethyl ether
obeys Raoult’s Law. At this temperature, what is the vapour pressure of diethyl ether over a
solution in which its mole fraction is 0.270? (2)
Q.19 Two sodium chloride solutions are separated by a semi permeable membrane. The concentration
of solution ‘A’ is 0.50 M and the concentration of solution ‘B’ is 0.250 M. Over time, there will
be a measurable movement of (1)
(a) Water from solution A to B. (b) Water from solution B to A.
(c) Sodium chloride from solution B to A (d) Sodium chloride from solution A to B
(e) two of these are correct.
Q.20 On the basis of the given observation in each case predict (a) whether i=1 ,i<1or i>1
(b) comment on the molecular state of the solute whether normal, association or
dissociation.
(i) ∆Tb : expected 0.82 K, observed 0.82 K
(ii) π: expected 1.8 bar , observed 2.1 bar
(iii) ∆Tf: expected 1.68K, observed 1.42 K (3)
Q.21 Of the following compounds, which are likely to increase in solubility as the temperature of the
solution increases?
(a) Glucose, C6H12O6 (b) CO2 (c) NaBr (d) CuSO4 (e) CH4
Q.22 A nurse prepared three injections of concentration 1.0%, 0.75% and 0.9% saline to be injected
intravenously to a patient. Which is the most suitable concentration to be used? Why? (2)
TOPIC: SOLID STATE
1. An alloy of gold and cadmium crystallizes with a cubic structure in which gold atoms occupy the
corners and cadmium atoms fit into face centres. What formula would you assign to the alloy?
2. Diamond and graphite are two different ‘polymorphic’ forms of carbon. What do you understand
by this statement?
3. NaCl and Cu are both conductors of electricity. What do you understand by this statement?
4. On heating crystals of KCl in potassium vapours, the crystal exhibiting a violet colour, why?
5. Explain the following observations:
i) Solids have high density and low compressibility.
ii) Melting point of crystalline solids is sharp whereas that of amorphous solid is not.
iii) Ionic solids have high melting and boiling point.
6. For octahedral coordination, what should be the range of radius ratio r+ / r- value?
7. Thallium chloride, TlCl crystallizes in either a simple cubic lattice or a face centred cubic lattice
of Clions with Tl+
cell is 3.8510-8
8. What is the difference between a tetrahedral void and an octahedral void.
9. Niobium crystallizes in a body centered cubic structure. If density is 8.55g/cm3
atomic radius of niobium, given that its atomic mass is 93u.
ions in the holes. If the density of the solid is 9gm/c.c. and edge of the unit
cm, what is the unit cell geometry?
10. What are 13-15 and 12-16 compound. Explain giving examples.
11. What is an antiferroelectric solid?
12. Classify the following as p-type or n-type semiconductor-
i) Ge doped with In (ii) B doped with Si
13. Iron II oxide has a cubic structure and each unit cell has side 5Å. If the density of the oxide is
4g/cm3
72g mol-1
14. Calculate the efficiency of packing in case of metal crystal for-
i) simple cubic ii) body centred cubic (iii) face centred cubic
15. Gold (at radius =0.144nm) crystallizes in FCC unit cell. What is the length of side of the cell?
16 Analysis shows that nickel oxide has the formula Ni0.98O.What fraction of Ni exist as Ni2+ and
Ni3+ ions?
17. Chromium metal crystallises with BCC lattice. The length of the unit cell edge is found to be 287
pm. Calculate the atomic radius. What would be the density of chromium in g/cm3
18 Differentiate between with diagram
i) Schottky and Frenkel defect. ii) Ferromagnetic and ferrimagnetic substances.
19. What is the total volume of atoms in a face-centred cubic unit cell of a metal with radius ‘r’?
20. In a crystalline solid, anions B are arranged in ccp. cations A are distributed equally between
tetrahedral and octahedral voids. If all the octahedral voids are occupied find formula.
. Calculate the number of Fe2+ and O2-
)
ions present in each unit cell. (Molar Mass of FeO =
TOPIC : ALCOHOLS,PHENOLS AND ETHERS
1. Unlike phenols ,alcohols are easily protonated. Why?
2. Give chemical tests to distinguish between i) Phenol and Cyclohexanol and ii) Benzyl
alcohol & 2-Propanol, iii) Phenol & Benzoic acid , iv) sec & tert-butanol.
3. Propose a suitable mechanism for the preparation of ethoxyethane from ethanol.
4. Name the reagents which are used in following conversions:
i) 1°alcohol to an aldehyde, ii) butan-2-one to butan-2-ol, iii) phenol to 2,4,6-
tribromophenol.
5 .Why Me3COH is less acidic than Me3COH although carbon is more electronegative than
Si?
6 .Which one is more acidic : phenol or cresol? Why?
7. Predict the major product of acid-catalysed dehydration of : i) 1-methylcyclohexanol and
ii) butanol
8. Ortho and para nitrophenols are more acidic than phenol. Explain this observation with
the help of resonating structures of corresponding phenoxide ions.
9. Phenol is acidic yet it doesn’t react with sodium bicarbonate.Why?
10. Account for the following:
i) Methyl phenyl ether reacts with HI to give phenol & methyl iodide and not iodobenzene
and methyl alcohol.
ii) Order of reactivity of HX towards the cleavage of ethers is: HI>HBr>HCl
iii) Alcohols are freely soluble in water while haloalkanes are not.
iv) Alcohols act as weak bases.
v) Phenol has a smaller dipole moment than methanol.
vi) Acidity of alcohols follows the order: 1°>2°>3°.
vii) Symmetrical ethers also possess a net dipole moment.
viii) Acid catalysed dehydration of t-butanol is faster than n-butanol.
ix) Sodium metal can be used for drying diethyl ether and benzene but not for an alcohol.
11. Describe the following :
i) Kolbe’s reaction
ii) Reamer Tiemann reaction
iii) Coupling reaction
iv) Schotten-Baumann reaction
v) Esterification
vi) Fischer esterification
vii) Williamson’s synthesis
12.What happens when:
i) Ethanoyl chloride is treated with phenol
ii) Phenol is reacted with neutral FeCl3.
iii) Phenetole reacts with HI at 373K
iv) Diethyl ether reacts with Cl2 in dark.
13. The products of the reaction between Ethanol & H2SO4 depend upon the conditions
applied. Justify.
14. Conversions:
i) Benzene to cumene
ii) Phenol to p-hydroxyazobenzene
iii) Methanol to ethanol
iv) Ethanol to sodium ethoxide
v) Chlorobenzene to phenol
vi) Sodium propoxide to propoxypropane
vii) Ethylmagnesiumbromide to 1-propanol
viii) Propanol to 2-methyl-2-propanol
15. Describe the following processes with example:
i) Protonation , ii) acetylation
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