試題詳解

2. Given that pure liquid A has vapor pressure x, and pure liquid B has vapor pressure y, with x ＞ y, calculate the mole fraction of A in the ideal A/B solution if the vapor above the solution is 20% A?
(A) y/(4x + y)
(B) 4y/(x+4y)
(C) x/(x+4y)
(D) 4x/(4x+y)
(E) 2y/(x + 2y)