Chemistry - Ionic Equilibrium Question with Solution | TestHub

When pure water is saturated with ${\mathrm{CaCO}}_3$ and ${\mathrm{CaC}}_2{\mathrm{O}}_4$, the concentration of calcium ion in the solution under equilibrium is $8.426\times 10^{-5}\mathrm{M}$. If the ratio of the solubility product of ${\mathrm{CaCO}}_3$ to that of ${\mathrm{CaC}}_2{\mathrm{O}}_4$ is 2.087 , what is the solubility product of ${\mathrm{CaCO}}_3$ in pure water?