SOLUTIONS
(a) Both assertion and reason are correct statements, and reason is the correct
explanation of the assertion.
(b) Both assertion and reason are correct statements, but reason is not the correct
explanation of the assertion.
(c) Assertion is correct, but reason is wrong statement.
(d) Assertion is wrong, but reason is correct statement.
1. Assertion: Molality is a better method to express concentration than molarity
Reason: Molality is defined in terms of mass of solvent and not mass of solution. (A)
2. Assertion: Soda bottles are sealed under high pressure.
Reason: High pressure increases the solubility of carbon dioxide gas. (A)
3. Assertion: There will not be any change in concentration of an ethanol and water mixture
containing 85% ethanol by volume on boiling.
Reason: It is because azeotropes boil out in constant composition. (D)
4. Assertion: Benzene and hexane form an ideal solution.
Reason: Both benzene and hexane are hydrocarbons. (C)
5. Assertion: 1 molar NaCl solution has higher boiling point than one molar urea.
Reason: NaCl dissociates into ions in solution. (A)
6. Assertion: A raw mango placed in concentrated salt solution loses water shrivel into
pickle.
Reason: The salt solution is hypotonic compared to the raw mango. (C)
7. Assertion: Helium is mixed with nitrogen and oxygen in diving cylinders
Reason: Helium has comparatively low KH value. (C)
8. Assertion: Ice containing dissolved sugar will melt at a higher temperature than pure ice.
Reason: Dissolving sugar in water leads to a depression in freezing point. (D)
9. Assertion: Molar mass of acetic acid in benzene calculated using colligative property is
almost double the actual value.
Reason: Acetic acid dimerises in solution. (A)
10. Assertion: Vapour pressure of a solution is more that of the pure solvent.
Reason: The solute particles occupy certain area of the surface of the solution which
reduces the amount of vapour. (D)
ELECTROCHEMISTRY
11. Assertion: It is possible to make a cell with a pair of same type of half cells.
Reason: Change in concentration varies the electrode potential. (A)
12. Assertion: When aqueous sodium chloride solution is electrolysed, Oxygen gas is
produced at the anode.
Reason: It is due to the overpotential for oxidation of water to oxygen. (A)
13. Assertion: Molar conductivity of an electrolyte increases with decrease in concentration.
Reason: The mobility of ions decrease with increase in concentration. (A)
, 14. Assertion: The electrode potential of standard hydrogen electrode is zero.
Reason: There is no potential difference at the electrode - solution interface in this case.
(C)
15. Assertion: Reduction of 1 mole of Cu2+ ions require 2 faraday of charge.
Reason: 1 Faraday is equal to the charge of 1 mole of electrons. (A)
16. Assertion: Fuel cells are pollution free.
Reason: Fuel cells use hydrogen like fuels along with oxygen gas for current production.
(B)
17. Assertion: Lechlanche cell gives constant voltage throughout its life.
Reason: The overall reaction of button cell does not involve any ion in solution whose
concentration can change during its life time. (D)
18. Assertion: Coating iron with zinc prevents rusting.
Reason: The coating of zinc prevents moist air to come in contact with the metal. (C)
19. Assertion: More negative the electrode potential greater is the power to act as oxidising
agent.
Reason: As the electrode potential becomes more negative there is greater tendency to
undergo oxidation. (D)
20. Assertion: Secondary cells are cells which can be recharged after use.
Reason: The products are electrolysed back to the initial reactants during recharge of the
cell. (A)
CHEMICAL KINETICS
21. Assertion: Hydrolysis of methyl ethanoate is a pseudo first order reaction.
Reason: Water is present in large excess and therefore its concentration remained
constant throughout the reaction. (A)
22. Assertion: Order of a reaction can be zero.
Reason: In the case of heterogeneous catalysis, the reaction becomes independent of
concentration at high concentration of the reaction. (A)
23. Assertion: The slowest elementary step in a complex reaction decides the rate of the
reaction.
Reason: The slowest elementary step always has the smallest molecularity. (C)
24. Assertion: A catalyst increases the rate of a reaction.
Reason: The catalyst increases the activation energy which in turn increases the rate of
the reaction. (C)
25. Assertion: Activation complex for the forward reaction will have lower energy than that for
the backward reaction in an exothermic reaction.
Reason: Reactants have greater energy than products for an exothermic reaction. (D)
26. Assertion: Increase in temperature increases rate of reaction.
Reason: More colliding molecules will have energy greater than threshold energy. (A)
27. Assertion: Unit of rate constant is independent of order of reaction.
Reason: The power of concentration terms in the rate equation keep changing with
change in order. (D)
28. Assertion: Increase in concentration of reactant will not change the rate for a zero order
reaction. .
Reason: Rate constant for a zero order reaction is a constant for a particular initial
(a) Both assertion and reason are correct statements, and reason is the correct
explanation of the assertion.
(b) Both assertion and reason are correct statements, but reason is not the correct
explanation of the assertion.
(c) Assertion is correct, but reason is wrong statement.
(d) Assertion is wrong, but reason is correct statement.
1. Assertion: Molality is a better method to express concentration than molarity
Reason: Molality is defined in terms of mass of solvent and not mass of solution. (A)
2. Assertion: Soda bottles are sealed under high pressure.
Reason: High pressure increases the solubility of carbon dioxide gas. (A)
3. Assertion: There will not be any change in concentration of an ethanol and water mixture
containing 85% ethanol by volume on boiling.
Reason: It is because azeotropes boil out in constant composition. (D)
4. Assertion: Benzene and hexane form an ideal solution.
Reason: Both benzene and hexane are hydrocarbons. (C)
5. Assertion: 1 molar NaCl solution has higher boiling point than one molar urea.
Reason: NaCl dissociates into ions in solution. (A)
6. Assertion: A raw mango placed in concentrated salt solution loses water shrivel into
pickle.
Reason: The salt solution is hypotonic compared to the raw mango. (C)
7. Assertion: Helium is mixed with nitrogen and oxygen in diving cylinders
Reason: Helium has comparatively low KH value. (C)
8. Assertion: Ice containing dissolved sugar will melt at a higher temperature than pure ice.
Reason: Dissolving sugar in water leads to a depression in freezing point. (D)
9. Assertion: Molar mass of acetic acid in benzene calculated using colligative property is
almost double the actual value.
Reason: Acetic acid dimerises in solution. (A)
10. Assertion: Vapour pressure of a solution is more that of the pure solvent.
Reason: The solute particles occupy certain area of the surface of the solution which
reduces the amount of vapour. (D)
ELECTROCHEMISTRY
11. Assertion: It is possible to make a cell with a pair of same type of half cells.
Reason: Change in concentration varies the electrode potential. (A)
12. Assertion: When aqueous sodium chloride solution is electrolysed, Oxygen gas is
produced at the anode.
Reason: It is due to the overpotential for oxidation of water to oxygen. (A)
13. Assertion: Molar conductivity of an electrolyte increases with decrease in concentration.
Reason: The mobility of ions decrease with increase in concentration. (A)
, 14. Assertion: The electrode potential of standard hydrogen electrode is zero.
Reason: There is no potential difference at the electrode - solution interface in this case.
(C)
15. Assertion: Reduction of 1 mole of Cu2+ ions require 2 faraday of charge.
Reason: 1 Faraday is equal to the charge of 1 mole of electrons. (A)
16. Assertion: Fuel cells are pollution free.
Reason: Fuel cells use hydrogen like fuels along with oxygen gas for current production.
(B)
17. Assertion: Lechlanche cell gives constant voltage throughout its life.
Reason: The overall reaction of button cell does not involve any ion in solution whose
concentration can change during its life time. (D)
18. Assertion: Coating iron with zinc prevents rusting.
Reason: The coating of zinc prevents moist air to come in contact with the metal. (C)
19. Assertion: More negative the electrode potential greater is the power to act as oxidising
agent.
Reason: As the electrode potential becomes more negative there is greater tendency to
undergo oxidation. (D)
20. Assertion: Secondary cells are cells which can be recharged after use.
Reason: The products are electrolysed back to the initial reactants during recharge of the
cell. (A)
CHEMICAL KINETICS
21. Assertion: Hydrolysis of methyl ethanoate is a pseudo first order reaction.
Reason: Water is present in large excess and therefore its concentration remained
constant throughout the reaction. (A)
22. Assertion: Order of a reaction can be zero.
Reason: In the case of heterogeneous catalysis, the reaction becomes independent of
concentration at high concentration of the reaction. (A)
23. Assertion: The slowest elementary step in a complex reaction decides the rate of the
reaction.
Reason: The slowest elementary step always has the smallest molecularity. (C)
24. Assertion: A catalyst increases the rate of a reaction.
Reason: The catalyst increases the activation energy which in turn increases the rate of
the reaction. (C)
25. Assertion: Activation complex for the forward reaction will have lower energy than that for
the backward reaction in an exothermic reaction.
Reason: Reactants have greater energy than products for an exothermic reaction. (D)
26. Assertion: Increase in temperature increases rate of reaction.
Reason: More colliding molecules will have energy greater than threshold energy. (A)
27. Assertion: Unit of rate constant is independent of order of reaction.
Reason: The power of concentration terms in the rate equation keep changing with
change in order. (D)
28. Assertion: Increase in concentration of reactant will not change the rate for a zero order
reaction. .
Reason: Rate constant for a zero order reaction is a constant for a particular initial
