plz answer quickly!!!!

Dear Student,

Let:

p_A = Vapour pressure of benzene=500 mm Hg

n= mole fraction of benzene

p_{B =} Vapour pressure of toluene= 200 mm Hg

p_{t  =} Total pressure  = 380 mm Hg

Using raoult's law for ideal solutions we have:

p_A n   +   p_B (1-n) = p_t

or

500 n + 200 (1-n) = 380

or

300 n = 180

or

n=0.6

Hence mole fraction of Benzene in the mixture is 0.6.