A system of propane and n-butane exists in two-phase vapor/liquid equilibrium at 10.0

题目

A system of propane and n-butane exists in two-phase vapor/liquid equilibrium at 10.0
bar and 323 K.The mole fraction of propane is about 0.67 in the vapor phase and about
0.40 in the liquid phase.Additional pure propane is added to the system,which is brought
again to equilibrium at the same T and P,with both liquid and vapor phases still present.
What is the effect of the addition of propane on the mole fractions of propane in the
vapor and liquid phases?

答案

这一题考查的是“杠杆原理（lever rule）”.从二元气液平衡相图上可以看出来,加入纯丙烷后,在同温同压下达到新的相平衡,此时丙烷在气相中的摩尔分数仍然是0.67,在液相中的摩尔分数仍然是0.40.设加入纯丙烷以前,体系...