Question

$K_{2}Hg{I}_4$ is $40\%$ ionised in its aqueous solution. The value of its van't Hoff factor is______

Answer 1

Answer: 1.8

$\alpha =\frac{i-1}{n^{\prime }-1}$
$K_{2}Hg{L}_4⟶2K^{+}+{\left[Hg{I}_4\right]}^{2-}$
$\therefore n^{\prime }=3$
$\therefore 0.40=\frac{i-1}{3-1}$
$\therefore i=(0.40\times 2)+1=1.8$