Chemistry - Liquid Solution Question with Solution | TestHub

$\begin{array}{rl}& \Delta {\mathrm{T}}_{\mathrm{f}}={\mathrm{ik}}_{\mathrm{f}}\mathrm{m}\\ & 0.2=\mathrm{i}\times 1.8\times 0.1\\ & \mathrm{i}=\frac{20}{18}=\frac{10}{9}\\ & \text{ For }{\mathrm{HA}}_{(\mathrm{aq})}\rightleftharpoons {\mathrm{H}}_{(\mathrm{aq})}^{+}+{\mathrm{A}}_{(\mathrm{aq})}^{-}\\ & \mathrm{t}=01\\ & \mathrm{t}={\mathrm{t}}_{\mathrm{eq}}1-\alpha \alpha \\ & \mathrm{i}=1+\alpha \\ & \frac{10}{9}=1+\alpha \\ & \alpha =\frac{1}{9}\\ & {\mathrm{K}}_{\mathrm{eq}}=\frac{\left[{\mathrm{H}}^{+}\right]\left[{\mathrm{A}}^{-}\right]}{[\mathrm{HA}]}=\frac{\mathrm{C}{\alpha }^2}{1-\alpha }\\ & 0.1{\left(\frac{1}{9}\right)}^2\\ & =\frac{1}{1-\frac{1}{9}}=\frac{1}{720}\\ & {\mathrm{K}}_{\mathrm{eq}}=1.38\times 10^{-3}\end{array}$