$HgCl_2$ is a covalent compound,sparingly soluble in water. The solubility increases by the addition of chloride ions due to:

When $AgCl$ is treated with $KCN$, what happens?

Copper sulphate solution reacts with $KCN$ to give

For the complex $ML_2$,the stepwise formation constants for the reactions:
$M + L \rightleftharpoons ML$
$ML + L \rightleftharpoons ML_2$
are $4$ and $3$ respectively. Hence,the overall stability constant for the reaction:
$M + 2L \rightleftharpoons ML_2$
is:

Which complex is formed when an aqueous solution of $NH_3$ is added to a $CuSO_4$ solution,resulting in a deep blue color?

How does ammonia react with a solution of $Cu^{2+}$?