Which of the following sulphides has the lowest solubility product?

The solubility product for salt $AB_2$ is $4 \times 10^{-12}$. Calculate its solubility.

Which of the following compounds is insoluble in acetic acid?

What is the value of $K_{sp}$ for a saturated solution of $Ba(OH)_2$ having $pH = 12$?

Calculate the solubility product of sparingly soluble salt $BA$ at $300 \ K$ if its solubility is $9.1 \times 10^{-3} \ mol \ dm^{-3}$ at same temperature.

The solubility of $BaSO_4$ in pure water (in $g \, L^{-1}$) is closest to
[Given: $K_{sp}$ for $BaSO_4$ is $1.0 \times 10^{-10}$ at $25^{\circ} C$. Molecular weight of $BaSO_4$ is $233 \, g \, mol^{-1}$]