Biphenyl, C12H10, is a nonvolatile, nonionizing solute that is soluble in benzene, C6H6. At 25 °C, the vapor pressure of pure benzene is 100.84 torr. What is the vapor pressure (in torr) of a solution made from dissolving 16.6 g of biphenyl in 26.0 g of benzene?

Answer 1

vapor pressure is dependent on the mole ratios.

vapor pressusre=100.84*Molebenzene/total moles

moles benzene=26/molmassBenzene

moles biphenyl=16.6/molmassBiphenyl

total moles add those two.