Class 12 Chemistry Chapter Solution MCQ And Answer (Abnormal Molar Masses) for AIIMS, NEET, JEE provides a comprehensive coverage of the fundamental concepts in the fields of Solutions Chemistry. It contains a variety of questions from previous years’ AIIMS, NEET and JEE papers.

Class 12 Chemistry Chapter Solution MCQ And Answer (Abnormal Molar Masses)

1. In which of the following solutions will the Van’t Hoff Factor for the solute be lesser than 1?

a) Sodium chloride in water

b) Benzoic acid in benzene

c) Acetic acid in benzene

d) Phenol in benzene

Answer: a

2. The Van’t Hoff Factor for a solution of glucose in water is equal to 1.

a) True

b) False

Answer: a

3. The depression of freezing point of a solution of acetic acid in benzene is – 0.2°C. If the molality of acetic acid is 0.1 m, then find the ratio of the normal mass to the abnormal mass. (Assume Kf of acetic acid = 4.0°C m-1)

a) 1.5

b) 0.8

c) 0.5

d) 0.2

Answer: c

4. What is the Van’t Hoff Factor for 1 mole of BaCl2, assuming 100% dissociation?

a) 0.33

b) 1

c) 3

d) 2

Answer: c

5. Which of the following aqueous solutions should have the least boiling point?

a) 1.0 M KOH

b) 1.0 M (NH₄)₂SO₄

c) 1.0 M K₂CO₃

d) 1.0 M K₂SO₄

Answer: a

6. The pH of a 2 M solution of a weak monobasic acid (HA) is 4. What is the value of the Van’t Hoff factor?

a) 0.00005

b) 1.005

c) 1.0005

d) 1.00005

Answer: d

7. Acetic acid associates as dimers in benzene. What is the Van’t Hoff factor (i) if the degree of association of acetic acid is 50%?

a) 0.25

b) 0.50

c) 0.75

d) 0.40

Answer: c

8. Only if the calculated molar mass is higher than the actual molar mass of the solute, the calculated molar mass is considered to be abnormal molar mass.

a) True

b) False

Answer: b

9. Which of the following statements is correct?

a) Solutes that dissociate in water have molar mass higher than the molar mass of the solute calculated theoretically

b) Solutes that associate in water have molar mass higher than the molar mass of the solute calculated theoretically

c) Solutes that dissociate in water experience a decrease in colligative properties

d) Colligative properties are independent of the number of particles of the solute in the solution

Answer: b

10. What is the value of the Van’t Hoff factor (i) for solutes that dissociate in water?

a) > 1

b) < 1

c) = 0

d) Not defined

Answer: a

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