question_answer

Benzene and toluene form nearly ideal solutions. At\[20{}^\circ C,\]the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at \[20{}^\circ C,\]for a solution containing 78 g of benzene and 46 g of toluene in torr is     AIEEE  Solved  Paper-2005

A) 53.5       

B)        37.5       

C)        25                          

D)        50

Correct Answer: D

Solution :

Mixture contains 78 g benzene = 1 mole benzene and 46 g toluene = 0.5 mole toluene Total mole of benzene and toluene =1.5 mol Mole fraction of benzene in mixture Vapour pressure of benzene,  Partial vapour pressure of benzene