Question

What is the correct representation for the solubility product of $ SnS_{2} $ ?

• A. $\left[S n^{2+}\right]\left[S^{2-}\right]^{2}$
• B. $\left[S n^{4+}\right]\left[S^{2-}\right]^{2}$
• C. $\left[S n^{2+}\right]\left[2 S^{2-}\right]$
• D. $\left[S n^{2+}\right]\left[2 S^{2-}\right]^{2}$

Answer 1

Answer: (A)

$S n S_{2}+a q \rightleftharpoons \underset{\text { solution }}{S n S_{2}} \rightleftharpoons S n^{2+}+2 S^{2-}$
Applying law of mass action to this equilibrium
$K=\frac{\left[S n^{2+}\right]\left[S^{1-}\right]^{2}}{\left[S n S_{2}\right]} $
Or $K\left[S n S_{2}\right]_{4}=\left[S n^{2+}\right]\left[S n^{2-}\right]^{2}$
since $\left[S n S_{2}\right]$, in solid state remain constant and therefore,
$K_{s p}=\left[S n^{2+}\right]\left[S^{2-}\right]^{2}$