Question

An aqueous solution of a salt $M{X}_2$ at certain temperature has a van't Hoff factor of $2$. The degree of dissociation for this solution of the salt is:
(JEE Main - 2016)

• A. $0.33$
• B. $0.50$
• C. $0.80$
• D. $0.67$

Answer 1

The correct option is B $0.50$

$M{X}_2\to M^{2+}+2X^{-}$

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

$\alpha =\frac{2-1}{3-1}=\frac{1}{2}=0.5$