MCQs on Solutions – Class 12
1.
If 2 moles of NaCl are dissolved in 1 kg of water, the molality of the solution is:
a) 1 m
b) 2 m
c) 0.5 m
d) 4 m
2.
Which of the following is not a colligative property?
a) Relative lowering of vapour pressure
b) Osmotic pressure
c) Depression of freezing point
d) Molal mass
3.
A 0.1 M solution of glucose and a 0.1 M solution of NaCl are prepared. Which will have higher osmotic pressure?
a) Glucose
b) NaCl
c) Both same
d) Cannot be predicted
4.
The vapour pressure of pure water at 25 °C is 23.8 mmHg. What will be the vapour pressure of a solution containing 1 mol of non-volatile solute in 55.5 mol of water?
a) 23.38 mmHg
b) 23.0 mmHg
c) 22.0 mmHg
d) 21.5 mmHg
5.
Henry’s law constant for CO₂ in water is high. This means:
a) CO₂ is very soluble in water
b) CO₂ is sparingly soluble in water
c) Solubility is independent of pressure
d) Solubility increases rapidly with temperature
6.
If 1 mole of NaCl is dissolved in 1 L water, the van’t Hoff factor (i) is:
a) 1
b) 2
c) 3
d) 0
7.
A solution boils at 100.52 °C. The ebullioscopic constant of water (Kb) = 0.52 K kg mol⁻¹. The molality of solute is:
a) 1 m
b) 0.5 m
c) 2 m
d) 0.1 m
8.
Which statement is correct?
a) Colligative properties depend on nature of solute.
b) Colligative properties depend on number of solute particles.
c) Colligative properties depend on solvent only.
d) Colligative properties are independent of concentration.
9.
The mole fraction of solute in a solution is 0.2. What is the mole fraction of solvent?
a) 0.8
b) 0.2
c) 1.2
d) 0.02
10.
A 5% (w/w) solution of glucose in water means:
a) 5 g glucose in 95 g water
b) 5 g glucose in 100 g solution
c) 5 g glucose in 100 mL solution
d) 5 g glucose in 100 g water
11.
The units of Henry’s law constant KH are:
a) mol L⁻¹ atm⁻¹
b) atm mol⁻¹ L
c) atm
d) mol L⁻¹
12.
An azeotrope is:
a) A mixture of liquids with the same composition in liquid and vapour phase
b) A mixture that boils at variable temperature
c) A mixture of solid and liquid
d) A mixture showing abnormal colligative properties
13.
Which of the following pairs shows positive deviation from Raoult’s law?
a) H₂O + C₂H₅OH
b) CHCl₃ + C₆H₆
c) H₂O + HCl
d) Acetone + CS₂
14.
Relative lowering of vapour pressure is equal to:
a) Mole fraction of solute
b) Mole fraction of solvent
c) Molality of solution
d) Molarity of solution
15.
The freezing point of 1 molal NaCl solution is nearly double the depression shown by 1 molal urea solution. Why?
a) NaCl is volatile
b) NaCl ionises giving more particles
c) NaCl reduces vapour pressure more
d) NaCl is heavier
16.
At higher altitudes, people use pressure cookers because:
a) Boiling point of water increases with pressure
b) Boiling point of water decreases with pressure
c) Vapour pressure of water decreases with temperature
d) None of the above
17.
The value of van’t Hoff factor (i) for K₂SO₄ is:
a) 2
b) 3
c) 1
d) 4
18.
Which one forms a maximum boiling azeotrope with water?
a) HNO₃
b) HCl
c) C₂H₅OH
d) CH₃COOH
19.
The molarity of pure water is approximately:
a) 1 M
b) 18 M
c) 55.5 M
d) 100 M
20.
If osmotic pressure of 0.01 M solution of a substance is 2.46 atm at 27 °C, the substance is:
(R = 0.0821 L atm K⁻¹ mol⁻¹)
a) Nonelectrolyte
b) Strong electrolyte
c) Non-volatile liquid
d) Colloid
21.
Cryoscopic constant (Kf) depends on:
a) Nature of solute
b) Nature of solvent
c) Both solute and solvent
d) Temperature only
22.
If solute associates in a solution, van’t Hoff factor (i) is:
a) > 1
b) < 1
c) = 1
d) Infinite
23.
In osmosis, solvent moves:
a) From concentrated solution to dilute
b) From dilute solution to concentrated
c) From high pressure to low pressure
d) In both directions equally
24.
Raoult’s law is applicable to:
a) Non-ideal solutions only
b) Ideal solutions only
c) Electrolyte solutions
d) Colloidal solutions
25.
A solution shows negative deviation from Raoult’s law when:
a) A–B interactions < A–A or B–B
b) A–B interactions > A–A or B–B
c) Solution behaves ideally
d) Solute associates in solution
Answer Key
- b
- d
- b
- a
- b
- b
- a
- b
- a
- b
- a
- a
- d
- a
- b
- a
- b
- a
- c
- b
- b
- b
- b
- b
- b
Sarvan sir- Chemistry For All 