Statement-1: Addition of ${\mathrm{HgI}}_2$ to aqueous solution of $\mathrm{KI}$ increases the freezing point.

Statement-2: A complex ${\mathrm{K}}_2\left[{\mathrm{Hgl}}_4\right]$ is formed.

When mercuric iodide is added to aqueous solution of KI the freezing point of the given solution increases. Mercuric Iodide will react with Potassium Iodide to form a complex as follows:

$\underset{4 \mathrm{ions}}{2\mathrm{KI}}+{\mathrm{Hgl}}_2\to \underset{3 \mathrm{ions}}{{\mathrm{K}}_2\left[{\mathrm{HgI}}_4\right]}$

This will decrease the number of ions in the solution and so Van't Hoff factor decreases which depend on the number of particles.