What will be the molar solubility S of a solid salt with general formula ${\mathrm{M}}_{\mathrm{x}}^{\mathrm{p}+}{\mathrm{X}}_{\mathrm{y}}^{\mathrm{q}-}$ ?

A solid salt,of the general formula, ${\mathrm{M}}_{\mathrm{x}}^{\mathrm{p}+}{\mathrm{X}}_{\mathrm{y}}^{\mathrm{q}-}$ with molar solubility ,S in equilibrium with its saturated solution may be represented by the equation,
${\mathrm{M}}_{\mathrm{x}}{\mathrm{X}}_{\mathrm{y}}\left(\mathrm{s}\right)⟶{\mathrm{xM}}^{\mathrm{p}+}\left(\mathrm{aq}\right)+{\mathrm{yX}}^{\mathrm{q}{-}^{\text{'}}}\left(\mathrm{aq}\right)$

$\text{ (where }\left.\mathrm{x}\times {\mathrm{p}}^{+}=\mathrm{y}\times {\mathrm{q}}^{-}\right)$

                                      $\text{ (where }\left.\mathrm{x}\times {\mathrm{p}}^{+}=\mathrm{y}\times {\mathrm{q}}^{-}\right)$

And its solubility product constant is given by
${\mathrm{K}}_{\mathrm{sp}}={\left[{\mathrm{M}}^{\mathrm{p}+}\right]}^{\mathrm{x}}{\left[{\mathrm{X}}^{\mathrm{q}-}\right]}^{\mathrm{y}}=\left(\mathrm{xS}{)}^{\mathrm{x}}\right(\mathrm{yS}{)}^{\mathrm{y}}$

${\mathrm{K}}_{\mathrm{SP}}= {\mathrm{x}}^{\mathrm{x}}·{\mathrm{y}}^{\mathrm{y}}·{\mathrm{S}}^{(\mathrm{x}+\mathrm{y})}$

${\mathrm{S}}^{(\mathrm{x}+\mathrm{y})}=\frac{{\mathrm{K}}_{\mathrm{sp}}}{{\mathrm{X}}^{\mathrm{x}},{\mathrm{Y}}^{\mathrm{y}}}\text{ or }\mathrm{S} = {\left({\mathrm{K}}_{\mathrm{sp}}/{\mathrm{X}}^{\mathrm{x}}·{\mathrm{Y}}^{\mathrm{y}}\right)}^{1/\mathrm{x}+\mathrm{y}}$