Question

The mole fraction of component A in the vapour phase is $x_1$ and mole fraction of component A in liquid mixture is $x_2(P_A^0$= vapour pressure of pure A; $P_B^0$ = vapour pressure of pure B).

• A. $\frac{\left(P_A^{\circ }{x}_2\right)}{x_1}$
• B. $\frac{P_A^{\circ }{x}_1}{x_2}$
• C. $\frac{P_A^{\circ }{x}_1}{x_2}$
• D. $\frac{P_B^{\circ }{x}_2}{x_1}$

Answer 1

The correct option is A

$\frac{\left(P_A^{\circ }{x}_2\right)}{x_1}$

$x_1=\frac{P_A^{\circ }xA}{P_{Total}}=\frac{P_A^{\circ }{x}_2}{P_{Total}}\therefore P_{Total}=\frac{P_A^{\circ }{x}_2}{x_1}$