The vapor pressure of pure benzene is 96.0 torr. The vapor pressure of pure toluene is 27.0 torr

Question

A.) Calculate the vapor pressure of benzene, C6H6, at 25 degrees Celsius in an ideal solution containing 1.68 mol of toluene.

B.) Calculate the vapor pressure of toluene,C7H8, at 25 degrees Celsius in an ideal solution containing 1.68 mol of benzene and 0.511 mol of toluene.

Answer 1

Can't do (A) without more info. But here is the solution to part (B).

See Raoults Law

Moles benzene = 1.68 mols

Moles toluene = 0.511

Total moles = 1.68 + 0.511 = 2.19 moles

Mole fraction of toluene = 0.511 mol / 2.19 mol = 0.233

Vapor pressure of toluene = 0.233 x 27.0 torr = 6.30 torr