Chemistry - Liquid Solution Question with Solution | TestHub

$$\text{ Mol.wt. }=\frac{k_f\times w\times 1000}{\Delta T_f\times W}=\frac{1.86\times 0.85\times 1000}{0.23\times 125}\approx 55\mathrm{gm}$$ Where $$\begin{array}{rl}& w=0.85\mathrm{g}\\ & W=125\mathrm{g}\\ & \Delta T_f=0^{\circ }\mathrm{C}-\left(-23^{\circ }\mathrm{C}\right)=23^{\circ }\mathrm{C}\end{array}$$ Now, $i=\frac{M_{\text{normal }}}{M_{\text{observed }}}=\frac{136.3}{55}=2.47$ $$\begin{array}{rl}& \underset{1-\alpha }{{\mathrm{ZnCl}}_2}\leftrightharpoons \underset{\alpha }{{\mathrm{Zn}}^{++}}+\underset{2\alpha }{2{\mathrm{Cl}}^{-}}\\ & \text{Van’t Hoff factor ( }i\text{ ) }\\ & =\frac{1-\alpha +\alpha +2\alpha }{1}=2.47\\ & \therefore \alpha =0.735=73.5\%\\ & \end{array}$$