The vapour pressure of pure benzene and toluene at a particular temperature are 100 mm and 50 mm respectively. Then the mole fraction of benzene in vapour phase in contact with equimolar solution of benzene and toluene is

Question

The vapour pressure of pure benzene and toluene at a particular temperature are 100 mm and 50 mm respectively. Then the mole fraction of benzene in vapour phase in contact with equimolar solution of benzene and toluene is (A) 0.67 (B) 0.75 (C) 0.33 (D) 0.50

Tardigrade Admin · Accepted Answer

Total vapour pressure, p text total =p1+p2 =100 + 50 =150 mm ∴ Mole fraction of benzene in solution, x =(p1/p1+p2) =(100/150)=(2/3) =0.67

Q. The vapour pressure of pure benzene and toluene at a particular temperature are $100 mm$ and $50 mm$ respectively. Then the mole fraction of benzene in vapour phase in contact with equimolar solution of benzene and toluene is

0.67

0.75

0.33

0.50

0.20

Total vapour pressure, $p_{total} = p_{1} + p_{2}$

$= 100 + 50$

$= 150 mm$

$∴$ Mole fraction of benzene in solution,

$x = \frac{p _{1}}{p _{1} + p _{2}}$

$= \frac{100}{150} = \frac{2}{3}$

$= 0.67$

Q. The vapour pressure of pure benzene and toluene at a particular temperature are 100mm and 50mm respectively. Then the mole fraction of benzene in vapour phase in contact with equimolar solution of benzene and toluene is