The solubility of $PbF_2$ in water at $25\,^{\circ}C$ is $\sim 10^{-3}\, M$. What is its solubility in $0.05\, M\, NaF$ solution? Assume the latter to be fully ionised.

What is the maximum concentration of equimolar solutions of ferrous sulphate and sodium sulphide so that when mixed in equal volumes,there is no precipitation of iron sulphide? (For iron sulphide,$K_{sp} = 6.3 \times 10^{-18}$).

Explain the equilibrium involving the dissolution of a solid in a liquid.

If the solubility product of $CuS$ is $9 \times 10^{-16}$,then what will be the maximum molarity of $CuS$ in an aqueous solution?

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.

At $T(K)$ in a saturated solution of $MgCO_3$ and $Ag_2CO_3$, if the concentration of $Mg^{2+}$ ion is $3.2 \times 10^{-5} \ M$, then the concentration of $Ag^{+}$ ion in the solution will be [Given: $K_{sp}(MgCO_3) = 1.6 \times 10^{-6}$ and $K_{sp}(Ag_2CO_3) = 8.0 \times 10^{-12}$ at $T(K)$]