Question

The vapor pressure of a volatile liquid can be determined by slowly bubbling a known volume of gas through it at a known temperature and pressure. In an experiment, 5.57 {\rm L} of {\rm{N}}_2 gas is passed through 7.2394 {\rm g} of liquid benzene, {\rm{C}}_6 {\rm{H}}_6, at 20.5^\circ {\rm C} and atmospheric pressure. The liquid remaining after the experiment weighs 5.2651 {\rm g}. Assuming that the gas becomes saturated with benzene vapor and that the total gas volume and temperature remain constant, what is the vapor pressure of the benzene in torr?