Question

What will happen to freezing point of a potassium iodide aqueous solution when mercuric Iodide as added to solution. Explain.

Answer 1

When mercuric iodide is added to aqueous solution of Potassium iodide, the freezing point of solution will increase.

Reason:-

Potassium iodide ionizes in water as

$KI⟶K^{+}+I^{-}$

When $Hg{I}_2$ is added to it, it forms complex with $KI$

$2KI+Hg{I}_2⟶K_2\left[Hg{I}_4\right]$

Hence, number of particle will decrease from $4$ to $3$. So, there would be less depression in freezing point and freezing point will increase.