Answer
Please see the work below.
Work Step by Step
$PbI_{2(s)} ⇌ Pb^{2+}_{(aq)} + 2I^{-}_{(aq)}$
$Ksp=[Pb^{2+}][I^{-}]^{2}$
The solubility product constant, Ksp ​, is the equilibrium constant for a solid substance dissolving in an aqueous solution. It represents the level at which a solute dissolves in solution.
For a general equation
$aA_{(s)}⇌cC_{(aq)}+dD_{(aq)}$
To solve for the Ksp it is necessary to take the molarities or concentrations of the products $C^{c} and D^ {d}$ and multiply them. If there are coefficients in front of any of the products, it is necessary to raise the product to that coefficient power(and also multiply the concentration by that coefficient).
$Ksp=[C]^{c}[D]^{d}$
The reactant, aA, is not included in the Ksp equation. Solids are not included when calculating equilibrium constant expressions, because their concentrations do not change the expression; any change in their concentrations are insignificant.
