The following is a rule of thumb: For a binary system in VLE at low pressure, the equilibrium vapor-phase mole fraction y₁ corresponding to an equimolar liquid mixture is approximately

where P^sat_i is a pure-species vapor pressure. Clearly, this equation is valid if Raoult’s law applies. Prove that it is also valid for VLE described by Eq. (13.19), with ln γ 1 = A x²₂ and ln γ₂ = A x²₁.

Eq. (13.19)

Transcribed Image Text:

Sat yi = sat sat