The K sp of Ag 2 CrO 4 is 1 . 1 × 1 0 - 1 2 at 298   K . The solubility (in mol   L - 1 ) of…

$\begin{array}{ccccc}{\text{Ag}}_2{\text{CrO}}_4\left(\mathrm{s}\right)& \rightleftharpoons & 2{\text{Ag}}^{+}\left(\mathrm{aq}\right)& +& {\text{CrO}}_4^{2-}\\ & & \left(2\text{S}\right) \text{molar}& & \left(\text{S}\right) \text{molar}\end{array}$
$\begin{array}{ccccc}{\text{AgNO}}_3\left(\mathrm{aq}\right)& ⟶& {\text{Ag}}^{+}\left(\mathrm{aq}\right)& +& {\text{NO}}_3^{-}\left(\mathrm{aq}\right)\\ & & \left(0\text{.}1\right) \text{molar}& & \left(0\text{.}1\right) \text{molar}\end{array}$
$\left[{\mathrm{Ag}}^{+}\right]=\left(2\mathrm{S}+0.1\right) \mathrm{molar}$
$\left[{\text{CrO}}_4^{2-}\right]=\left(\mathrm{S}\right)\text{ molar}$
Here, $\mathrm{S}$ is the solubility of ${\mathrm{Ag}}_2{\mathrm{CrO}}_4$ in aqueous  ${\mathrm{AgNO}}_3$.

$\Rightarrow$${\left[{\text{Ag}}^{+}\right]}^{\mathrm{2 }}\left[{\text{CrO}}_4^{2-}\right]={\left(2\text{S}+0\text{.}1\right)}^2\left(\text{S}\right)=1\text{.}1\times 10^{-12}$
                      $\text{S}\ll 0\text{.}1$
$\Rightarrow$$$\begin{gathered} {\left(0.1\right)}^2\left(\mathrm{S}\right)=1.1\times {10}^{-12}={10}^{-2}\times \mathrm{S} \\ \mathrm{S}=1.1\times {10}^{-10} \mathrm{M} \end{gathered}$$