Benzene and toluene form nearly ideal solutions. At 20∘, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20∘ for a solution containing 78g of benzene and 46g of toluene in torr is
According to Rault's law-
PB=P0B×XB=75×78787878+4692=75×11+0.5=50 torr