Question

At 25$^{\circ}$C, the solubility product of Hg$_2Cl_2$ in water is $3.2 \times 1^{-17} mol^3 dm^{-9}$ What is the solubility of Hg$_2Cl_2$ in water at 25$^{\circ}$C?

• A. $1.2 \times 10^{-12} M$
• B. $3.0 \times 10^{-6} M$
• C. $2 \times 10^{-6} M$
• D. $1.2 \times 10^{-16} M$
• E. $5.2 \times 10^{-6 } M$

Answer 1

Answer: (C)

$Hg_2Cl_2 \rightarrow Hg_2^{2+} +2Cl^-$
$ \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, K_{sp} =4S^3 =32 \times 10^{-18}$
$\, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, \, S=2 \times 10^{-6} M$