Question

A storage battery contains a solution of $H_2{SO}_4$ $38$ by weight. What will be the Vant Hoff factor if the $\Delta T_{f\left(experiment\right)}$ in $\mathrm{29.08.}$ $[Given{K}_1=1.86{mol}^{-1}Kg]$.

Answer 1

From freezing point formula,

$T_f=i{K}_{f}M$

where $m$= molarity of the solution

Now $38g$ of $H_{2}S{O}_4$ present in $100g$ of solution.

Mass of solvent= $100-38=62g$

$\therefore m=\left(\frac{38}{98}\right)/\left(\frac{62}{1000}\right)=6.25$

$\Rightarrow i=\frac{T_f}{K_{f}m}=\frac{29.08}{1.86\times 6.25}$

$\Rightarrow i=2.5$