Question

$M{X}_2$ dissociates into $M^{2+}$ and $X^{-}$ ions in an aqueous solution with a degree of dissociation of $\alpha$ of $0.5$. The ratio of the observed depression of freezing point of the aqueous solution to the value of the depression of freezing point in the absence of ionic dissociation is:

Answer 1

$$\begin{array}{ccccc}M{X}_2& \rightleftharpoons & M^{2+}& +& 2X^{-}\\ (1-\alpha )& & \alpha & & 2\alpha \end{array}$$
$i=1-\alpha +\alpha +2\alpha$
$i=1+2\alpha$
$i=1+2\times 0.5=2$