Collect. Czech. Chem. Commun. 1979, 44, 1698-1714

New possibilities of applications of the Barker quasi-lattice theory. Prediction of gE and hE of binary systems whose one component is formed by n-alkanes

Vladimír Dohnal, Robert Holub and Jiří Pick

Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


For binary systems of the type an arbitrary component + n-alkane we derived relations, on the basis of the Barker theory and on the basis of the group contribution concept, for predicting gE and hE from one system to another when the n-alkane length is changed. To carry out the prediction it is not necessary to evaluate any adjustable parameters. The developed method was tested using a large number of different systems covering alcohols, amines, ketones, esters, chlorinated derivatives of hydrocarbons, aromatic hydrocarbons and n-alkanes from n-pentane to n-hexadecane. The results of predictions are in very good agreement with experimental data in the cases, when the n-alkanes involved are not longer than n-decane. Systematic regular deviations in hE in the cases, when at least one of n-alkanes involved is longer, can be explained by the presence of orientation effects in the pure longer n-alkanes. The correction suggested by us for these effects improves considerably results obtained. The developed method appears to be suitable for the systematic prediction of excess quantities of systems of the given type and represents an effective test of the Barker theory.