At some temperature the vapour pressure of pure benzene, `C_(6) H_(6)` is 0 . 256 bar and vapour pressure of toluene, `C_(6) H_(5) CH_(3)` is 0 . 0 925 bar, if the mole fraction of toluene in a solution is 0 . 60
(i) What is the total vapour pressure of the solution ?
(ii) Calculate the composition of the vapour phase in terms of mole fraction.

Explanation

`P_("ben")^(@)=0.256 "bar",P_("tol")^(@)=0.0925"bar"`
Mole fraction of toluene = 0.60
Mole fraction of benzene = 0.40
`P_(T)=P_("ben")^(@)x_("ben")+P_("tol")^(@)x_("tol")=0.256xx0.40+0.09205xx0.60=0.1024+0.0550.158" bar"`