A reasonably general expression for vapour-liquid phase equilibrium at low to moderate pressure is Φ<sub>i</sub> y<sub>i</sub> P = Y<sub>i</sub> x<sub>i</sub> f<sub>i</sub>° where, Φ is a vapor fugacity component, Y<sub>i</sub> is the liquid activity co-efficient and f<sub>i</sub>° is the fugacity of the pure component i. the K<sub>i</sub> value (Y<sub>i</sub> = K<sub>i</sub> x<sub>i</sub>) is therefore, in general a function of

Correct Answer: Temperature, pressure and liquid composition x<sub>i</sub> only