Assign $A, B, C, D$ from the given type of reaction.
$HgS(s) + Na_2S(aq) \rightleftharpoons Na_2[HgS_2](aq)$

The precipitation occurs if the ionic product is

Assign $A, B, C, D$ from the given type of reaction: $PbCl_2(s) + \text{Hot water} \longrightarrow Pb^{2+}(aq) + 2Cl^{-}(aq)$

The solubility of a sparingly soluble salt $AB_2$ in water is $1.0 \times 10^{-5} \ mol \ L^{-1}$. Its solubility product is .......?

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 . . . . . .

Find the concentration of the ion which is first precipitated at the point when the third ion starts precipitating,if $AgNO_3$ is added gradually to a solution that contains $0.1 \ M \ Cl^{-}$,$0.1 \ M \ Br^{-}$,and $0.1 \ M \ I^{-}$.
Given that:

Salt	$K_{sp}$
$AgCl$	$2 \times 10^{-10}$
$AgBr$	$5 \times 10^{-13}$
$AgI$	$9 \times 10^{-17}$