The vapour pressures of two liquids A and B in their pure states are in the ratio of 1: 2 . A binary solution of A and B contains A and B in the mole proportion of 1: 2 . The mole fraction of A in the vapour phase of the solution will be

Step-by-step solution

Given, p _ A : p _ B =1: 2 array ll & p _ B =2 p _ A Similarly & n _ A n _ B = 1 2 array x _ A = 1 1+2 = 1 3 and x _ B = 2 1+2 = 2 3 Total pressure, p _ T = p _ A x _ A + p _ B x _ B aligned &=p_ A 1 3 +2 p_ A 2 3 &= 1 3 p_ A + 4 3 p_ A &= 5 3 p_ A aligned