Determination of Infinite-Dilution Partial Molar Excess Entropies and Enthalpies from the Infinite-Dilution Activity Coefficient Data of Alkane Solutes Diluted in Longer-Chain-Alkane Solvents

Abstract

Reliable values of partial molar excess entropies and partial molar excess enthalpies at infinite dilution of short-carbon-chain alkanes diluted in long-carbon-chain alkanes are required for the critical verification of conventional activity coefficient models. They are scarce in the literature because of the lack of pertinent criteria for the selection of extensive data for infinite-dilution activity coefficients, γi∞. The criteria for the selection of literature data for ln γi∞ have been established, and reliable values of partial molar excess entropies and partial molar excess enthalpies at infinite dilution have been determined. It has been shown that both are positive and that each quantity is correlated as a linear function with a dispersion force parameter. It has been demonstrated that only a quite limited part of each quantity is accurately predicted by conventional activity coefficient models.