Which of the following reagents can be used to separate $AgCl$ and $AgI$?

The solubility of $BaSO_4$ in water is $2.33 \times 10^{-3} \ g/L$. Its solubility product is....... (Molar mass of $BaSO_4 = 233 \ g/mol$)

Solubility product expression of salt $MX_4$ which is sparingly soluble with a solubility $(S)$ can be given as

The solubility of $BaSO_{4}$ in water is $2.42 \times 10^{-3} \ g \ L^{-1}$ at $298 \ K$. The value of solubility product $(K_{sp})$ will be (Given molar mass of $BaSO_{4} = 233 \ g \ mol^{-1}$)

In the reaction $Fe(OH)_{3(s)} \rightleftharpoons Fe^{3+}_{(aq)} + 3OH^{-}_{(aq)}$, if the concentration of $OH^{-}$ ions is decreased by $\frac{1}{4}$ times, then the equilibrium concentration of $Fe^{3+}$ will increase by: (in $\times$)

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.