Question

A solute a has 2 is to 3 molar ratio of toluene to benzene the vapour pressure of benzene and toluene is 25 degree centigrade and 9528 the mole fraction of toluene vapour is

Answer 1

The mole fraction of toluene in the vapour = 0.548

Explanation:

Given: A solute a has 2:3 molar ratio of toluene:benzene. The vapour pressure of benzene and toluene at 25° C are 95 and 28 bar respectively.

Find: The mole fraction of toluene vapour.

Solution:  

For the equimolar solution of benzene and toluene, the mole fraction of benzene and toluene are 0.5 each.

Total pressure P = Pb + Pr = P(B to O)Xb + P(T to O)Xt

P = 160 * 0.5 + 60 * 0.5

P = 110

The mole fraction of toluene in the vapour phase in contact with an equimolar solution of benzene and toluene.

Yt = Pt/P

Yt = P(T to O) Xt / P

    = 60 * 0.5 / 110  

    = 0.27

Therefore 0.548 is the answer.