Chapter 8, Problem 129E

The overall formation constant for ${\text{HgI}}_4{}^{2-}\text{ is 1}{\text{.0×10}}^{30}.$ That is,

$1.0\times {10}^{30}=\frac{\left[{\text{HgI}}_4{}^{2-}\right]}{\left[{\text{Hg}}^{2+}\right]{\left[{\text{I}}^{-}\right]}^4}$

What is the concentration of ${\text{Hg}}^{2+}\text{in 500}\text{.0 mL}$ of a solution that was originally $0.010M{\text{ Hg}}^{2+}$ and had $\text{65 g of KI}$ added to it? The reaction is
${\text{Hg}}^{2+}\left(aq\right)+4{\text{I}}^{-}\left(aq\right)\rightleftharpoons {\text{HgI}}_4{}^{2-}\left(aq\right)$