Chemistry - Liquid Solution Question with Solution | TestHub

We have${\text{M}}_2=\frac{{\text{K}}_{\text{f}}\times {\text{w}}_2\times 1000}{\Delta {\text{T}}_{\text{f}}\times {\text{w}}_1}$

when${\text{w}}_1=$weight of solvent = 50 g

${\text{w}}_2=$weight of solute = 1.00 g

${\text{K}}_{\text{f}}=$molal depression constant

$={\text{5.12 K kg mol}}^{-1}$

Substituting the values of various terms involved in the above equation, we get

${\text{M}}_2=\frac{\text{5.12}{\text{ K kg mol}}^{-1}\times \text{1.00 g}\times 1000{\text{ g kg}}^{-1}}{\text{0.40}\times 50\text{ g}}$

$=256{\text{ g mol}}^{-1}$

Thus, molar mass of the solute = 256 g/​mol