Evaluation of Heterodimerization Constant from Solid-Liquid and Vapor-Liquid Equilibrium Data

Activity coefficients obtained from the solid-liquid equilibrium data were used to fit the isobaric vapor-liquid equilibrium data to evaluate the vapor-phase equilibrium constant of heterodimerization of the system propanoic acid-trifluoroethanoic acid. The found hetero-dimerization constant is several times higher than that estimated on the basis of the "double-geometric-mean" rule and its temperature dependence has the form ln K AB = 7 196.7/ T - 26.80.