The volume of the water needed to dissolve $1 \ g$ of $BaSO_4$ $(K_{sp} = 1.1 \times 10^{-10})$ at $25 \ ^oC$ is ..... $litre$.

Calculate solubility $(mol \ dm^{-3})$ of a sparingly soluble electrolyte $AB$ at $298 \ K$ if its solubility product is $1.6 \times 10^{-5}$?

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.

Consider two Group $IV$ metal ions $X^{2+}$ and $Y^{2+}$. $A$ solution containing $0.01 \ M$ $X^{2+}$ and $0.01 \ M$ $Y^{2+}$ is saturated with $H_2S$. The pH at which the metal sulphide $YS$ will form as a precipitate is . . . . . . (Nearest integer). (Given: $K_{sp}(XS)=1 \times 10^{-22}$ at $25^{\circ} C$,$K_{sp}(YS)=4 \times 10^{-16}$ at $25^{\circ} C$,$[H_2S]=0.1 \ M$ in solution,$K_{a1} \times K_{a2}(H_2S)=1.0 \times 10^{-21}$,$\log 2=0.30, \log 3=0.48, \log 5=0.70$)

At $25^{\circ}C$,the solubility product $(K_{sp})$ of $Zn(OH)_2$ is $10^{-14}$. If $NH_4OH$ is $50\%$ dissociated,what will be the concentration of zinc in a $0.1 \ M$ $NH_4OH$ solution?

Which of the following reactions with $H_2S$ does not produce metallic sulphide?