Question

At $\text{30}{}^{\text{o}}\text{C}$ the solubility of $A{g}_{2}C{O}_3(K_{sp}=8\times {10}^{-12})$ would be greatest in one litre of

• A. $0.05MN{a}_{2}C{O}_3$
• B. $0.05MAgN{O}_3$
• C. pure water
• D. $0.05NN{H}_3$

Answer 1

Answer: (D)

$A{g}_{2}C{O}_3\rightleftharpoons 2A{g}^{+}C{O}_3^{2-}$
Due to the common ion effect, the solubility decreases, so the solubility of $A{g}_{2}C{O}_3$ would be greatest in $1L$ of $0.05MN{H}_3$ due to the absence of common ion either $A{g}^{+}$or $C{O}_3^{2-}+A{g}^{+}$ form complex with $N{H}_3$
$A{g}^{+}+2N{H}_3\rightleftharpoons {\left[Ag{\left(N{H}_3\right)}_2\right]}^{+}$