Thermodynamic properties of (an ethyl ester plus a branched alkane). XV. H-m(E) and V-m(E) values for (an ester plus an alkane)

Abstract

This paper presents H-m(E) and V-m(E) measurements taken at T = 298.15 K and at the atmospheric pressure of 100.65 kPa for 22 binary mixtures composed of one of four ethyl esters (methanoate, ethanoate, propanoate, and pentanoate) and one of seven alkane isomers, C-6 to C-8. The H-m(E) of four binary mixtures of ethyl propanoate and pentanoate with n-C-6 and n-C-8, measured at the conditions mentioned above are also presented. The results indicate that the mixing process is endothermic for all the mixtures, with H-m(E) varying regularly with the components chain length, increasing with alkane chain length and decreasing with the acid chain length in the ester. The V-m(E) values vary also regularly in a manner similar to that of the H-m(E.) slight contractions are observed for (ethyl pentanoate + 2-methylpentane). A new form of a polynomial equation used previously was employed to correlate the experimental values of the excess quantities and yielded good results in all cases. In addition, the behaviour of these mixtures is explained in terms of an interaction model proposed in previous work. (C) 2002 Elsevier Science Ltd. All rights reserved.