At a Given Temperature, You Have a Mixture of Benzene

Multiple Choice

At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene (vapor pressure of pure toluene = 290 torr) . The mole fraction of benzene in the vapor above the solution is 0.590. Assuming ideal behavior, calculate the mole fraction of toluene in the solution.

A) 0.778
B) 0.359
C) 0.213
D) 0.590
E) 0.641