question_answer

The vapour pressure of a solvent A is 0.80 atm  When a non-volatile substance B is added to this solvent its vapour pressure drops to 0.6 atm. What is mole fraction of B in solution                                 [MP PMT 2000, 01]

A)                 0.25       

B)                 0.50

C)                 0.75       

D)                 0.90