General
✓✗The freezing point of the solvent is lowered on adding a non-volatile solute because
- the solute freezes first
- the solvent becomes more volatile
- the vapour pressure of the solution becomes equal to that of the solid solvent at a lower temperature
- the solute raises the vapour pressure
General
✓✗A maximum boiling azeotrope is formed by solutions showing
- large negative deviation from Raoult's law
- ideal behaviour
- large positive deviation from Raoult's law
- no interaction between components
General
✓✗Which of the following statements are correct?
A. Molality is independent of temperature.
B. The vapour pressure of a solution of a non-volatile solute is directly proportional to the mole fraction of the solvent.
C. A minimum boiling azeotrope is formed by solutions showing negative deviation.
D. The osmotic pressure of a solution is directly proportional to its absolute temperature.
Choose the correct answer from the options given below.
A. Molality is independent of temperature.
B. The vapour pressure of a solution of a non-volatile solute is directly proportional to the mole fraction of the solvent.
C. A minimum boiling azeotrope is formed by solutions showing negative deviation.
D. The osmotic pressure of a solution is directly proportional to its absolute temperature.
Choose the correct answer from the options given below.
- A, B and D only
- A, B, C and D
- A and C only
- B, C and D only
General
✓✗Equal masses of two non-electrolytes, X (molar mass 60 g mol−1) and Y (molar mass 180 g mol−1), are dissolved separately in the same mass of water. The ratio ΔTf(X) : ΔTf(Y) is
- 9 : 1
- 1 : 1
- 1 : 3
- 3 : 1
General
✓✗For an ideal solution, the volume change on mixing (ΔmixV) is
- zero
- equal to the volume of solvent
- negative
- positive
General
✓✗The Henry's law constants of gases A and B in water at 298 K are 1.0 × 105 bar and 1.0 × 103 bar. If both gases are at the same partial pressure, the ratio of their mole fractions in water (xA : xB) is
- 1 : 10
- 1 : 100
- 1 : 1
- 100 : 1
General
✓✗The molality of a solution containing 9.8 g of H2SO4 (molar mass 98 g mol−1) in 250 g of water is
- 0.04 m
- 0.25 m
- 0.10 m
- 0.40 m
General
✓✗The mass of glucose (180 g mol−1) to be dissolved per litre to make a solution isotonic with blood (osmotic pressure 7.65 atm at 310 K, R = 0.0821 L atm mol−1 K−1) is
- 54.1 g
- 27.1 g
- 102.8 g
- 17.6 g
General
✓✗A solute is 100% trimerised in a solvent. If its normal molar mass is 60 g mol−1, its observed molar mass is
- 120 g mol−1
- 20 g mol−1
- 60 g mol−1
- 180 g mol−1
General
✓✗The density of a 3 M aqueous NaCl solution is 1.25 g mL−1. Its molality is (molar mass of NaCl 58.5 g mol−1)
- 2.25 m
- 2.40 m
- 3.00 m
- 2.79 m
General
✓✗In water-saturated air, the mole fraction of water vapour is 0.02. If the total pressure of the saturated air is 1.2 atm, the partial pressure of dry air is
- 0.98 atm
- 1.176 atm
- 1.76 atm
- 1.18 atm
General
✓✗Two solutions having the same osmotic pressure at a given temperature are called
- hypotonic solutions
- ideal solutions
- hypertonic solutions
- isotonic solutions
General
✓✗Which of the following is correct about the dissolution of a gas in a liquid?
- It increases with temperature for all gases
- It is always endothermic
- It is unaffected by pressure
- It is generally exothermic, so solubility falls as temperature rises
General
✓✗The KH value of a given gas in water increases with temperature. This means that
- the solubility does not depend on temperature
- the solubility of the gas decreases with increase in temperature
- the solubility of the gas increases with temperature
- the gas becomes non-ideal
General
✓✗A solution containing 10 g per dm3 of urea (molar mass = 60 g mol−1) is isotonic with a 5% (mass/volume) solution of a non-volatile solute. The molar mass of this non-volatile solute is
- 350 g mol−1
- 200 g mol−1
- 300 g mol−1
- 250 g mol−1