Chemistry - Ionic Equilibrium Question with Solution | TestHub

The ${\text{K}}_{\text{sp}}$ of $\text{FeS}=4\times {10}^{-19}$ at $298\text{K}\text{.}$ The minimum concentration of ${\text{H}}^{\text{+}}$ ions required to prevent the precipitation of $\text{FeS}$ from a $\text{0}\text{.01}\text{M}$ solution ${\text{Fe}}^{2+}$ salt by passing  ${\text{H}}_{\text{2}}\text{S}$

(Given${\text{H}}_{\text{2}}\text{S}$${\text{k}}_{{\text{a}}_{\text{1}}}\times {\text{k}}_{{\text{b}}_{\text{1}}}={10}^{-21}$)