Chemistry - Liquid Solution Question with Solution | TestHub

Given: $n_A=n_B=10$

Initially, the mole fraction is $X_A=X_B=0.5$.

When half of the liquid is converted into vapor, the remaining liquid composition changes due to the preferential evaporation of the more volatile component A.

For an ideal solution, the total pressure $P$ is given by Raoult's Law:

$$P=X_A{P}_A^0+X_B{P}_B^0$$

Using the Rayleigh relation for half vaporization, the average vapor pressure is:

$$P=\sqrt{P_A^0{P}_B^0}$$

Substituting the given values:

$$P=\sqrt{200\times 100}=\sqrt{20000}=141.4mmHg$$

Therefore, the pressure is $141.4mmHg$ (Option D).