Which of the following would increase the solubility of $Pb(OH)_2$?

The solubility of $AgCl$ at $20 \, ^oC$ is $1.435 \times 10^{-3} \, g/L$. The solubility product $(K_{sp})$ of $AgCl$ is:

The solubility product of $PbS$ is $3.4 \times 10^{-28}$. If $[Pb^{2+}] = 1 \times 10^{-2} \ mol/L$,what concentration of $[S^{2-}]$ is required to precipitate $PbS$?

The solubility of $AgBr$ with solubility product $5.0 \times 10^{-13}$ at $298 \ K$ in $0.1 \ M$ $NaBr$ solution would be:

How many grams of $CaC_2O_4$ will dissolve in distilled water to make $1 \, L$ of a saturated solution (in $, g$)? The solubility product $(K_{sp})$ of $CaC_2O_4$ is $2.5 \times 10^{-9} \, mol^2 \, L^{-2}$ and its molar mass is $128 \, g \, mol^{-1}$.

Equal volumes of $0.002 \, M$ solutions of sodium iodate and cupric chlorate are mixed together. Will it lead to precipitation of copper iodate?
(For cupric iodate $K_{sp} = 7.4 \times 10^{-8}$)