Calculate the solubility product of sparingly soluble salt $BA$ at $27^{\circ} C$ if its solubility is $1.8 \times 10^{-5} \ mol \ dm^{-3}$ at same temperature.

The solubility product of Lead sulphate,$PbSO_4$ is $1.3 \times 10^{-8}$. Calculate its solubility in pure water. The molecular mass of $PbSO_4 = 303 \ g \ mol^{-1}$.

Assign $A, B, C, D$ from the given type of reaction.
$HgS(s) + Na_2S(aq) \rightleftharpoons Na_2[HgS_2](aq)$

In qualitative analysis,the metals of group $I$ can be separated from other ions by precipitating them as chloride salts. $A$ solution initially contains $Ag^{+}$ and $Pb^{2+}$ at a concentration of $0.10 \, M$. Aqueous $HCl$ is added to this solution until the $Cl^{-}$ concentration is $0.10 \, M$. What will the concentrations of $Ag^{+}$ and $Pb^{2+}$ be at equilibrium? ($K_{sp}$ for $AgCl = 1.8 \times 10^{-10}$,$K_{sp}$ for $PbCl_2 = 1.7 \times 10^{-5}$)

Silver ions are added to a solution with $[Br^{-}] = [Cl^{-}] = [CO_3^{2-}] = [AsO_4^{3-}] = 0.1 \ M$. Which compound will precipitate with the lowest $[Ag^{+}]$ concentration?

If the solubility product of $HgSO_4$ is $6.4 \times 10^{-5}$,then its solubility is: