Excess heat capacities of alkan-1-ol–n-alkane systems at low alcohol concentrations. Description in terms of association

Abstract

The association model proposed formerly has been used together with the other models to predict to excess heat capacities of alkan-1-ol–n-alkane systems for concentrations up to 0.02 mole fraction of the alcohol. All of the model parameters (i.e. standard entropies and standard enthalpies of association) have been estimated from the spectroscopic data of pure ethanol. The prediction accuracy of the proposed model of successive association taking into account both linear and cyclic multimers is fairly good, slightly but distinctly higher than that of the monomer–tetramer model. It disagrees with the conception of predominance of tetramers in the solutions studied as was suggested by Costas and Patterson. The other models give quite unacceptable results.