PREDICTION OF THE EXCESS HEAT-CAPACITIES OF 1-ALKANOL -LIQUID PROPERTIES( ALKANE SYSTEMS ON THE BASIS OF PURE)

The partial molar excess heat capacities of 1-alkanols at infinite dil ution within the range 283-313 K and the excess heat capacities, C(p)E , of 28 (C1-C-12) 1-alkanol + alkane systems within the range 200-368 K were predicted by means of the athermal two-constant Mecke-Kempter m odel. The model parameters were determined on the basis of the propert ies of pure substances. For dilute solutions (less than 0.2 alcohol mo le fraction) the excess heat capacities estimated agree well with the experimental values, the average deviation in C(p)E for 435 data point s being 0.5 J K-1 mol-1. For the alcohol-rich solutions the average de viation in C(p)E is larger (1.5 J K-1 mol-1, based on 273 data points) and may indicate the presence of interactions which are not caused by hydrogen bonding. The results presented indicate that hydrogen bondin g effects predominate in the excess heat capacities of 1-alkanol + alk ane solutions.