Question

A solute $X$ when dissolved in a solvent associate to form a pentamer. The value of van't Hoff factor ($i$) for the solute will be:

• A. $0.5$
• B. $5$
• C. $0.2$
• D. $0.1$

Answer 1

The correct option is C $0.2$

$nA⟶{\left(A\right)}_n$

initially $1mol$ $0$

after assoociation $1-\alpha$ $\alpha /n$

$i=1-\alpha +\frac{\alpha }{n}$

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

$i=\frac{1}{5}=0.2$