Answer
Balanced equation:
$ PbBr_2(s) \lt -- \gt Pb^{2+}(aq) + 2 Br^{-}(aq)$
$K_{sp} = [Pb^{2+}] \times [Br^{-}]^2$
Work Step by Step
1. Identify the ions in the compound:
$Pb^{2+}$ and $Br^{-}$
2. Write the dissociation equation, where the solid ionic compound produces its ions in the water:
$ PbBr_2(s) \lt -- \gt Pb^{2+}(aq) + Br^{-}(aq)$
Balance the equation:
$ PbBr_2(s) \lt -- \gt Pb^{2+}(aq) + 2 Br^{-}(aq)$
3. To get the $K_{sp}$ expression, multiply the ions concentrations, where their balancing coefficients are the exponent of the molarities.
$K_{sp} = [Pb^{2+}]^1 \times [Br^{-}]^2$
$K_{sp} = [Pb^{2+}] \times [Br^{-}]^2$
