Which of the following compounds does not dissolve in ammonium hydroxide solution?

The volume of water required to dissolve $0.1 \ g$ $PbCl_2$ to get a saturated solution (in $mL$) is (Given $K_{sp}(PbCl_2) = 3.2 \times 10^{-8}$; Atomic mass of $Pb = 207 \ u$, $Cl = 35.5 \ u$)

Assign $A, B, C, D$ from the given type of reaction.
$SrC_2O_4(s) + 2HCl(aq) \longrightarrow SrCl_2(aq) + H_2C_2O_4(aq)$

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 $K_{sp} = 7.4 \times 10^{-8}$)

The solubility product of silver bromide $(AgBr)$ is $5.0 \times 10^{-13}$. How much potassium bromide $(KBr)$ (molar mass $120 \, g \, mol^{-1}$) should be added to $1 \, L$ of $0.05 \, M$ silver nitrate $(AgNO_3)$ solution to initiate the precipitation of $AgBr$?

The solubility of $AgCl$ in $0.1 \text{ M } NaCl$ is $S \text{ mol/L}$. If the solubility product of $AgCl$ is $1.8 \times 10^{-10}$, then $S$ is approximately: