If molality of the dilute solution is doubled, the value of molal depression constant (K_f) will be?

(1) doubled

(2) halved

(3) tripled

(4) unchanged

The temperature dependent term among the following is -

At 100°C the vapour pressure of a solution of 6.5 g of a solute in 100 g water is 732 mm. If K_b = 0.52, the boiling point of this solution will be

(1) 100°C

(2) 102°C

(3) 103°C

(4) 101°C

Which of the following statements about the composition of the vapour over an ideal 1:1

molar mixture of benzene and toluene is correct? Assume that the temperature is

constant at 25°C.

(Given, vapour pressure data at 25°C, benzene = 12.8 kPa, toluene = 3.85 kPa)

1. The vapour will contain a higher percentage of toluene

2. The vapour will contain equal amounts of benzene and toluene

3. Not enough information is given to make a prediction

4. The vapour will contain a higher percentage of benzene

Which one is not equal to zero for an ideal solution?

1. ΔH_mix 

2. ΔS_mix

3. ΔV_mix

4. ΔP=P_Observed-P_Raoult

Of the following 0.10 m  aqueous solutions, which one will exhibit the largest freezing

point depression?

1. KCl

2. C₆H₁₂O₆

3. Al₂(SO₄)₃

4. K₂SO₄

The freezing point depression constant format is -1.86°C m^-1. If 5.00g Na₂SO₄ dissolved

in 45.0 g H₂O, the freezing point is changed by -3.82°C. Calculate the van't Hoff factor

for NaSO4

1. 2.63

2. 3.11

3. 0.381

4. 2.05

The van't Hoff factor, i for a compound which undergoes dissociation in one solvent and

association in other 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. Which change will cause the vapour pressure of

the solution to increase ?

1. Addition of NaCl

2. Addition of Na₂SO₄

3. Addition of 1.00 molal KI

4. Addition of water

A solution of acetone in ethanol:

1. Shows a negative deviation from Raoult's law.

2. Shows a positive deviation from Raoult's law.

3. Behaves like a near ideal solution.

4. Obeys Raoult's law.