## Introductory Chemistry (5th Edition)

$KSP$= $[A^{2+}{}_{(aq)} ][B^{-}{}_{(aq)}]^{2}$
Since we know the charge of B and the overall product, we can write the decomposition equation as shown below: $AB_{2}{}_{(s)} --> A^{2+}{}_{(aq)} + 2B^{-}{}_{(aq)}$ Now to write out solubility product constant expression, we don't include solids and only include the concentration of the aqueous solutions in terms of Products/Reactants where the coefficients in front of the species become exponents for that species. Therefore, the Ksp expression is shown below: $KSP$= $[A^{2+}{}_{(aq)} ][B^{-}{}_{(aq)}]^{2}$