Consider a binary mixture of a and b at T = 300 K and P = 40 kPa. A graph of the fugacity of species a as a function of mole fraction is shown below. Use Henry’s law as the reference state for species a and the Lewis/Randall rule for species b. Show all your work.

(a) What is the Henry’s law constant, Ha, for species a?

(b) What is the activity coeffi cient for species a at xa = 0.4? At xa = 0.8? (remember the Henry’s law reference state!). Show your work.

(c) Is the activity coeffi cient for species b at xa = 0.4 greater than or less than 1? Explain.

(d) Is the a-b interaction stronger than the pure species interactions? Explain.

(e) Consider the vapor phase to be ideal. What is the vapor-phase mole fraction of a in equilibrium with 40% liquid a?

Transcribed Image Text:

(kPa) 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 642 O T = 300 K P = 40 kPa 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Xa 1