At `40^(@)C` the vapour pressure of pure liquids, benzene and toluene, are `160 mm Hg` and `60 mm Hg` respectively. At the same temperature, the vapour pressure of an equimolar solution of the liquids, assuming the ideal solution will be:

Options

A. 140 mm H
B. 110 mm Hg
C. 220 mm Hg
D. 100 mm Hg

Answer

B

Explanation

Equimolar quantit of Benzene and Toluence will have mole fraction 0.5 each.
partial vapour pressure of Benzene
`= 160 xx 0.5 = 80 mm. Hg `
Partial vapour pressure of Toluene
`=60 xx 0.5 = 30 mm. Hg`.
Total vapour pressure of two liquids.
`=80 +30 =110 mm H g `. ltbr.