Which of the following is least soluble in water?

If the $K_{sp}$ of a saturated solution of $Mg(OH)_2$ is $4 \times 10^{-12}$,then the $pH$ is equal to:

Which of the following happens when $NH_{4}OH$ is added gradually to the solution containing $1 \ M \ A^{2+}$ and $1 \ M \ B^{3+}$ ions?
Given: $K_{sp}[A(OH)_{2}] = 9 \times 10^{-10}$ and $K_{sp}[B(OH)_{3}] = 27 \times 10^{-18}$ at $298 \ K$.

If the $K_{sp}$ of $AgCl$ is $10^{-10}$,what is the volume of the solution required to prepare a saturated solution of $1.43 \ g$ of $AgCl$? $[M.W. = 143]$

Assign $A, B, C, D$ from the given type of reaction.
$2AgNO_3 + Na_2C_2O_4 \longrightarrow Ag_2C_2O_4 \downarrow + 2NaNO_3$

For a sparingly soluble salt $A_pB_q$,what is the relationship between its solubility $(S)$ and solubility product $(K_{sp})$?