Question

Concentration of $A{g}^{+}$ ions in a saturated solution of $A{g}_{2}Cr{O}_4$ at ${20}^o$C is $1.5\times {10}^{-4}$ mol $L^{-1}$, At ${20}^0$C, the solubility product of $A{g}_{2}Cr{O}_4$ is:

• A. $5.6\times {10}^{-12}$
• B. $1.68\times {10}^{-10}$
• C. $5.6\times {10}^{-11}$
• D. $1.68\times {10}^{-11}$

Answer 1

The correct option is A $5.6\times {10}^{-12}$

Let us the problem.

$A{g}_2{C}_2{O}_4\left(s\right)\Rightarrow \underset{2s}{2A{g}^{+}}\left(aq\right)+\underset{s}{C_2{O}_4^{2-}}$

$K_{SP}=\left[A{g}^{+}\right]=2.2\times {10}^{-4}M$

Therefore,

$\left[C_2{O}_4^{2-}\right]=\frac{2.2\times {10}^{-4}}{2}M=1.1\times {10}^{-4}M$

$\therefore K_{SP}=\left(2.2\times {10}^{-4}\right)\left(1.1\times {10}^{-4}\right)$

$=5.6\times {10}^{-12}$