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

The molar solubility of $Zn(OH)_{2}$ in $0.1 \, M \, NaOH$ solution is $x \times 10^{-18} \, M$. The value of $x$ is ...... . (Nearest integer)
(Given : The solubility product of $Zn(OH)_{2}$ is $2 \times 10^{-20}$)

If $pH$ of a saturated solution of $Ba(OH)_2$ is $12$,the value of its $K_{sp}$ is

The solubility product of $Ag_2CO_3$ and $FeCO_3$ in water at $25 \, ^\circ C$ are $4 \times 10^{-12}$ and $2.5 \times 10^{-11}$ respectively. If $S_1$ and $S_2$ are their solubilities in water respectively when dissolved separately,then $S_1/S_2$ is

Which of the following is the least soluble carbonate?

The solubility product of $Ni(OH)_2$ at $298 \ K$ is $2 \times 10^{-15} \ mol^3 \ dm^{-9}$. The $pH$ value of its aqueous and saturated solution is