Question

Benzoic acid is dissolved in benzene, van't Hoff factor will be:

• A. 1
• B. 0.5
• C. 1.5
• D. 2

Answer 1

Answer: (B)

When benzoic acid dissolves in benzene it will be dimerised due to the inter molecular hydrogen bonding

$2C_6{H}_{5}COOH\rightleftharpoons {\left(C_6{H}_{5}COOH\right)}_2$

Von't Hoff factor = $\frac{\text{ number of particles after dissociation/association }}{\text{ number of particles before dissociation / association }}=\frac{1}{2}$

$=0.5$