試題詳解

23. Liquid A has vapor pressure x. Liquid B has vapor pressure y, and x>y.What is the mole fraction of A in the liquid mixture if the vapor above the solution is 30% A?
(A)0.3y/(0.7x+0.3y)
(B) 0.7y/(0.3x+0.7y)
(C) 0.3x/(0.3.xc+0.7y)
(D)0.7x/(0.7x+0.3y)
(E) none of these