The $pH$ at which $Mg(OH)_2$ $[K_{sp} = 1 \times 10^{-11}]$ begins to precipitate from a solution containing $0.10 \ M$ $Mg^{2+}$ ions is . . . . . .

The solubility of a salt of a weak acid $MX$ (e.g.,phosphoric acid salts) increases at lower $pH$. Explain with equations.

The concentration of $KI$ and $KCl$ in a solution containing both is $0.001 \ M$ each. If $20 \ mL$ of this solution is added to $20 \ mL$ of a saturated solution of $AgI$ in water,what will happen?

What mass of $AgI$ will dissolve in $1.0 \ L$ of its saturated solution? [Given $: K_{sp}(AgI) = 1.0 \times 10^{-16} ; (At. \ wt. \ Ag = 108; I = 127)$]

For the following Assertion and Reason,the correct option is
Assertion $(A) :$ When $Cu^{2+}$ and sulphide ions are mixed,they react together extremely quickly to give a solid.
Reason $(R) :$ The equilibrium constant of $Cu^{2+}_{(aq)} + S^{2-}_{(aq)} \rightleftharpoons CuS_{(s)}$ is high because the solubility product is low.

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.