What are the products formed when an aqueous solution of $CuCl_2$ and $(NH_4)_2S$ are mixed?

Derive the solubility product $(K_{sp})$ expression for the following sparingly soluble salts:
$(i)$ Two ions having $MX$ formula
$(ii)$ Three ions having $MX_{2}$ or $M_{2}X$ types
$(iii)$ Four ions having $AX_{3}$ or $A_{3}X$ type salts
$(iv)$ Five ions $A_{2}X_{3}$ or $A_{3}X_{2}$ type salts.

$A$ solution which is $10^{-3} \ M$ each in $Mn^{2+}, Fe^{2+}, Zn^{2+},$ and $Hg^{2+}$ is treated with $10^{-16} \ M$ sulphide ion. If $K_{sp}$ of $MnS, FeS, ZnS,$ and $HgS$ are $10^{-15}, 10^{-23}, 10^{-20},$ and $10^{-54}$ respectively,which one will precipitate first?

What is the molar solubility of $Al(OH)_3$ in $0.2 \ M \ NaOH$ solution? Given that,the solubility product of $Al(OH)_3 = 2.4 \times 10^{-24}$.

Equal volumes of $0.02 \ M$ $CaCl_2$ and $0.00004 \ M$ $Na_2SO_4$ solutions are mixed. Will a precipitation of $CaSO_4$ occur? $(K_{sp} = 2.4 \times 10^{-5})$

The solubility of a sparingly soluble salt $AB_2$ is $18.78 \times 10^{-4} \text{ g/dm}^3$. What is its solubility product? (Molar mass of $AB_2 = 187.8 \text{ g mol}^{-1}$)