Chapter 15, Problem 47E

Consider the reaction:

   ${\text{NH}}_{\text{4}}\text{HS}\left(\text{s}\right)\rightleftharpoons {\text{NH}}_{\text{3}}\left(\text{g}\right)+{\text{H}}_{\text{2}}\text{S}\left(\text{g}\right)$

At a certain temperature, ${\text{K}}_{\text{c}}=\text{8}.\text{5}\times \text{1}{0}^{-\text{3}}$ . A reaction mixture at this temperature containing solid NH₄HS has [NH₃] = 0.166 M and [H₂S] = 0.166 M. Will more of the solid form, or will some of the existing solid decompose as equilibrium is reached?