What volume of water in $L$ is required to dissolve $1 \, g$ of $BaSO_4$ at $25 \, ^\circ C$? $(K_{sp} = 1.1 \times 10^{-10})$

The solubility product of $PbI_{2}$ is $8.0 \times 10^{-9}$. The solubility of lead iodide in $0.1 \ M$ solution of lead nitrate is $x \times 10^{-6} \ mol/L$. The value of $x$ is ....... .(Rounded off to the nearest integer)
$[$Given: $\sqrt{2}=1.41]$

If the solubility product $(K_{sp})$ of a sparingly soluble salt $MX_2$ at $25 \, ^\circ C$ is $1.0 \times 10^{-11}$,what is the solubility of the salt in $mol \, L^{-1}$ at this temperature?

The solubility products of $NiS$,$ZnS$,$CdS$,and $HgS$ are $4.7 \times 10^{-5}$,$1.6 \times 10^{-24}$,$8 \times 10^{-27}$,and $4 \times 10^{-53}$ respectively. An aqueous solution contains $Ni^{2+}$,$Zn^{2+}$,$Cd^{2+}$,and $Hg^{2+}$ of equal concentration. $H_2S$ gas was passed into this solution very slowly. The first and the last ions that precipitate as sulphides are respectively.

Which from the following equations represents the relation between solubility ($S$ in $mol \ L^{-1}$) and solubility product $(K_{sp})$ for a salt $B_3A_2$?

$Mg(OH)_2$ is precipitated when $NaOH$ is added to a solution of $Mg^{2+}$. If the final concentration of $Mg^{2+}$ is $10^{-10} \ M$,the concentration of $OH^{-} \ (M)$ in the solution is (Given: Solubility product for $Mg(OH)_2 = 5.6 \times 10^{-12}$)