The vapour pressure of pure liquids A and B are 450 and 700 mm of Hg at 350 K respectively. If the total vapour pressure of the mixture is 600 mm of Hg, the composition of the mixture in the solution is

Question

The vapour pressure of pure liquids A and B are 450 and 700 mm of Hg at 350 K respectively. If the total vapour pressure of the mixture is 600 mm of Hg, the composition of the mixture in the solution is (A) xA=0.4, xB=0.6  (B) xA=0.6, xB=0.4 (C) xA=0.3, xB=0.7 (D) xA=0.7, xB=0.3

Tardigrade Admin · Accepted Answer

p text tot = p A 0 x A + p B 0 x B 600=450 x A +700(1- x A ) 600=450 x A +700-700 x A -100=-250 x A x A =(100/250)=(2/5) =0.4 x B =1- x A =1-0.4 =0.6

Q. The vapour pressure of pure liquids $A$ and $B$ are $450$ and $700 mm$ of $H g$ at $350 K$ respectively. If the total vapour pressure of the mixture is $600 mm$ of $H g$ , the composition of the mixture in the solution is

$x_{A} = 0.4, x_{B} = 0.6$

$x_{A} = 0.6, x_{B} = 0.4$

$x_{A} = 0.3, x_{B} = 0.7$

$x_{A} = 0.7, x_{B} = 0.3$

$p_{tot} = p_{A}^{0} x_{A} + p_{B}^{0} x_{B}$
$600 = 450 x_{A} + 700 (1 - x_{A})$
$600 = 450 x_{A} + 700 - 700 x_{A}$
$- 100 = - 250 x_{A}$
$x_{A} = \frac{100}{250} = \frac{2}{5}$
$= 0.4$
$x_{B} = 1 - x_{A} = 1 - 0.4$
$= 0.6$

Q. The vapour pressure of pure liquids A and B are 450 and 700mm of Hg at 350K respectively. If the total vapour pressure of the mixture is 600mm of Hg, the composition of the mixture in the solution is

xA​=0.4,xB​=0.6

xA​=0.6,xB​=0.4

xA​=0.3,xB​=0.7

xA​=0.7,xB​=0.3