Question

What would be the solubility of silver chloride in 0.10 molar $NaCl$ solution?
($K_{sp}$ for $AgCl$ solution $=1.20\times {10}^{-10})$

• A. $0.1M$
• B. $1.2\times {10}^{-9}M$
• C. $1.2\times {10}^{-6}M$
• D. $1.2\times {10}^{-10}M$

Answer 1

Answer: (B)

$1.2\times {10}^{-9}M$

The expression for the solubility product of $AgCl$ is $K_{sp}=\left[A{g}^{+}\right]\left[C{l}^{-}\right]$.

In presence of 0.1 M $NaCl$ solution, $\left[A{g}^{+}\right]=s$ and $\left[C{l}^{-}\right]=0.1+s$.
But, $K_{sp}=1.2\times {10}^{-10}$.

Substitute values in the expression for the solubility product.
$1.2\times {10}^{-10}=s(0.1+s)=s^2+0.1s$. As s<<<1

Hence, $s=1.2\times {10}^{-9}$.