Which of the following compounds is insoluble in acetic acid?

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

In a qualitative analysis, $Bi^{3+}$ is detected by the appearance of a precipitate of $BiO(OH)(s)$. Calculate the $pH$ when the following equilibrium exists at $298 \text{ K}$:
$BiO(OH)(s) \rightleftharpoons BiO^{+}(aq) + OH^{-}(aq)$,
$K = 4 \times 10^{-10}$
(Given: $\log 2 = 0.3010$)

When solid $Pb(NO_3)_2$ is added to $1 \, L$ of $H_2SO_4$ $(1 \times 10^{-3} \, M)$ to make the concentration of $Pb(NO_3)_2$ equal to $0.002 \, M$,what will happen? $(K_{sp} \text{ of } PbSO_4 = 1.3 \times 10^{-8})$

The solubility of $BaCl_2$ is $4 \times 10^{-6} \ M$. Calculate its $K_{sp}$. Also,find its new solubility in the presence of $10^{-2} \ M \ Ba(OH)_2$.

The solubility product of a sparingly soluble salt $AX_2$ is $3.2 \times 10^{-11}$. Its solubility in $mol/L$ is: