Isobaric vapour-liquid equilibrium data of the 1,2-dichloroethane-water system at 101.3 kPa

Isobaric vapour-liquid equilibrium data for the 1,2-dichloroethane-water system were calculated on the assumption of ideal behaviour of the vapour phase on using the van Laar equation for activity coefficients of the components in the liquid phase. The parameters of the van Laar equation were calculated from the solubility of 1,2-dichloroethane in water and of water in 1,2-dichloroethane determined experimentally in this work. On using the solubility data, the parameters of the heteroazeotropic point at the pressure of 101.3 kPa were also calculated.

Applicability of the van Laar equation to correlation of strongly non-ideal systems

The performed analysis of the van Laar equation and its comparison with the results of analyses of the Redlich-Kister, NRTL and Wilson equations demonstrate that the Redlich-Kister equation have approximately the same range of applicability, the NRTL equation with a suitable choice of the parameter α allowing to attain higher limiting activity coefficients. For moderately asymmetric systems, the Wilson equation provides higher activity coefficients than other two-parameter equations but lower than the three-parameter ones. On the contrary, for very asymmetric systems, the Wilson equation allows to reach on the whole the highest limiting activity coefficients.