Chemistry - Liquid Solution Question with Solution | TestHub

The depression in freezing point is given by the formula:

$\Delta T_f=K_f\times m$

Substituting the given values, $\Delta T_f=0.2\text{ K}$ and $m=0.18\text{ m}$:

$0.2=K_f\times 0.18$

$K_f=\frac{0.2}{0.18}$

$K_f=\frac{20}{18}=1.11{\text{ K kg mol}}^{-1}$

Answer: $1.11\mathrm{K}\mathrm{kg}{\mathrm{mol}}^{-1}$