p_A and p_B are the vapour pressure of pure liquid components, A and B, respectively of an ideal binary solution.
If X_A represents the mole fraction of component A, the total pressure of the solution will be:

1. p_A + X_A (p_B-p_A)
2. p_A + X_A (p_A-p_B)
3. p_B + X_A (p_B-p_A)
4. p_B + X_A (p_A-p_B)

The freezing point depression constant for water is 1.86 ^oC m^-1. If 5.00 g Na₂SO₄ is dissolved in 45.0 g H₂O, the freezing point is changed by -3.82 ^oC. The Van’t Hoff factor for Na₂SO₄ is:

The van’t Hoff factor, i, for a compound that undergoes
dissociation and association in a solvent is, respectively:

1. Less than one and less than one.
2. Greater than one and less than one.
3. Greater than one and greater than one.
4. Less than one and greater than one.

An aqueous solution is 1.00 molal in KI. The vapour pressure of the solution can be increased by:

1. Addition of NaCl

2. Addition of Na₂SO₄

3. Addition of 1.00 molal Kl

4. Addition of water

A solution of sucrose (molar mass = 342 g mol^–1) has been prepared by dissolving 68.5 g of sucrose in 1000 g of water. The freezing point of the solution obtained will be: 
(k_f for water = 1.86 K kg mol^–1)
1. –0.372 ^oC
2. –0.520 ^oC
3. +0.372 ^oC
4. –0.570 ^oC

A 0.0020 m aqueous solution of an ionic compound Co(NH₃)₅(NO₂)Cl freezes at -0.0073 ^oC. The number of moles of ions that 1 mol of ionic compound produces on being dissolved in water will be:
(K_f = -1.86 ^oC/m)

0.5 molal aqueous solution of a weak acid (HX) is 20 % ionised. The lowering in the freezing point of the solution will be:
[K_f for water = 1.86 K kg mol^-1]

1. -1.12 K

2. 0.56 K

3. 1.12 K

4. -0.56 K

A solution containing 10 g/dm³ of urea (molecular mass = 60 g mol^-1) is isotonic with a 5 % solution of a non-volatile solute. The molecular mass of this non-volatile solute is:

1.00 g of non-electrolyte solute (molar mass 250 g mol^-1) was dissolved in 51.2 g of benzene. If the freezing point depression constant, K_f of benzene is 5.12 mol^-1 kg K, the freezing point of benzene will be lowered by:

1. 0.4 K

2. 0.3 K

3. 0.5 K

4. 0.2 K

A solution of acetone in ethanol: