Question

in a solvent 50% of benzoic acid dimerises while the rest ionises. determine molar mass of acid which is observed and also its van't hoff factor.

Answer 1

hope it helps you understand

Answer 2

Answer:

The observed molar mass of benzoic acid is 162.67 g/mol and van't hoff factor is 0.75.

Explanation:

Degree of hydrolysis = α = 50% = 0.50

n = 2

i = van't hoff factor

$\alpha =(1-i)\times \frac{n}{n-1}$

$0.50=(1-i)\times \frac{2}{2-1}$

i = 0.75

$i=\frac{\text{Calculated molar mass}}{\text{observed molar mass}}$

$0.75=\frac{122 g/mol}{\text{observed molar mass}}$

Observed molar mass  =$\frac{122 g/mol}{0.75}=162.67 g/mol$