What is the solubility product $(K_{sp})$ of calcium phosphate in pure water? $[S = \text{molar solubility}]$

What is the solubility product $(K_{sp})$ of a binary sparingly soluble salt $BA$ if a $100 \text{ mL}$ saturated solution of the salt contains $10^{-4} \text{ moles}$ at room temperature?

Calculate the solubility in $mol \ dm^{-3}$ of sparingly soluble salt $BA$ if its solubility product is $4.9 \times 10^{-13}$ at the same temperature.

$A_{3}B_{2}$ is a sparingly soluble salt of molar mass $M \ g \ mol^{-1}$ and solubility $x \ g \ L^{-1}$. The solubility product satisfies $K_{sp} = a(\frac{x}{M})^{5}$. The value of $a$ is ...... . (Integer answer)

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.

If the solubility product constant $(K_{sp})$ of $Ni(OH)_2$ is $1.9 \times 10^{-15}$,the molar solubility of $Ni(OH)_2$ in $1.0 \ M \ NaOH$ is: