Chemistry - Ionic Equilibrium Question with Solution | TestHub

${\mathrm{Bi}}_2{\mathrm{S}}_3$ will get dissociated as:

$$\begin{gathered} {\mathrm{Bi}}_2{\mathrm{S}}_3\rightleftharpoons 2{\mathrm{Bi}}^{+3}+3{\mathrm{S}}^{-2} \\ 2\mathrm{s} 3\mathrm{s} \end{gathered}$$

Here,

 $$\begin{gathered} {\mathrm{K}}_{\mathrm{sp}}={\left(2\mathrm{s}\right)}^2{\left(3\mathrm{s}\right)}^3=108 {\mathrm{s}}^5 \\ \mathrm{s}={\left(\frac{{\mathrm{K}}_{\mathrm{sp}}}{108}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$5$}\right.} \\ \mathrm{s}={\left(\frac{1.08\times {10}^{-73}}{108}\right)}^{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$5$}\right.} \\ \mathrm{s}={10}^{-15} \mathrm{mol} {\mathrm{L}}^{-1} \end{gathered}$$