Question

Consider the following statements and arrange in the order of true/false as given in the codes.
$S_1$: Vapour pressure is a colligative property.
$S_2$: Freezing point of a solution is always lower than that of the pure solvent.
$S_3$: Acetic acid undergoes association in benzene. The molar mass of acetic acid, determined by elevation of boiling point is always higher than its normal molar mass.
$S_4$: Osmotic pressure measurements can be used for determination of molar mass of polymers.

• A. FFFF
• B. FTTT
• C. TTTT
• D. TFTF

Answer 1

Answer: (B)

FTTT

The relative lowering in the vapour pressure $(S_1:\frac{\Delta P}{P})$ is a colligative property.

The addition of a non-volatile in the solvent results in the depression in the freezing point. Hence, the freezing point of a solution is always lower than that of the pure solvent.

In benzene, acetic acid undergoes association. Hence, the molar mass of acetic acid, determined by the elevation of the boiling point is always higher than its normal molar mass as it includes the molar mass of more than one monomer.

The molar mass of polymers is determined by the osmotic pressure measurements.

Option B is correct.