Chemistry - Liquid Solution Question with Solution | TestHub

By Raoult's Law ${\mathrm{P}}_{\mathrm{T}}={\mathrm{P}}_{\mathrm{P}}^{\circ }{\mathrm{X}}_{\mathrm{P}}+{\mathrm{P}}_{\mathrm{Q}}^{\circ }{\mathrm{X}}_{\mathrm{Q}}$ $$\begin{array}{rl}& {\mathrm{P}}_{\mathrm{P}}^{\circ }=80\text{ torr }\\ & {\mathrm{X}}_{\mathrm{P}}=\frac{3}{5}\\ & {\mathrm{P}}_{\mathrm{Q}}^{\circ }=60\text{ torr }\end{array}$$ $$\begin{array}{rl}{\mathrm{X}}_{\mathrm{Q}}& =\frac{2}{5}\\ {\mathrm{P}}_{\mathrm{T}}& =80\times \frac{3}{5}+60\times \frac{2}{5}\\ & =48+24\\ {\mathrm{P}}_{\mathrm{T}}& =72\text{ torr. }\end{array}$$ Related Theory Solutes which dissociate or associate in a particular solution will not obey Raoult's law. Raoult's law applies to solutions containing non-volatile solute only. Raoult's law cannot be applied to concentrated solutions.