Question

Which of the following metal sulphides has maximum solubility in water?

• A. $CdS(K_{sp}=36\times {10}^{-30})$
• B. $FeS(K_{sp}=11\times {10}^{-20})$
• C. $HgS(K_{sp}=32\times {10}^{-54})$
• D. $ZnS(K_{sp}=11\times {10}^{-22})$

Answer 1

Answer: (B)

$FeS(K_{sp}=11\times {10}^{-20})$

Solubility product of AB-type compounds are,

$AB=S^2$

So solubility of sulphide in water $=\sqrt{K_{sp}}$

Also, higher is the $K_{sp}$, higher will the solubility

So $FeS$ will have maximum solubility.