Question

The substance A, when dissolved in solvent B, shows the molecular mass corresponding to $A_3$. The van"t Hoffs factor will be:

• A. 1
• B. 2
• C. 3
• D. 1/3

Answer 1

The correct option is D 1/3

$\underset{1-\alpha }{3A}\to \underset{\alpha /3}{A_3}$
$i=1-\alpha =\alpha /3$
($\alpha =100$%)
$=1-1+\frac{1}{3}=\frac{1}{3}$