Excess enthalpy of ethanol + n-alkane (C6-C9) or cyclohexane or diisopropyl ether mixtures at 298.15 K: Measurement and modeling

Abstract

Flow microcalorimeter was used to measure the excess molar enthalpy (HmE) for ethanol (1) + n-alkanes or cyclohexane or diisopropyl ether (2) systems at 298.15 K. The plot for HmE versus x1 are tilted toward y-axis with a maxima at x1~0.4 and for equimolar mixture the HmE vary as: n-nonane > n-octane > cyclohexane > n-heptane > n-hexane > DIPE. The results were qualitatively discussed in terms of intermolecular interactions. For the theoretical interpretation of the experimental HmE values, Flory–Treszczanowicz–Benson association model (FTB) based on Mecke-Kempter association in alcohol and Graph theoretical approach were applied. Graph theoretical approach and FTB model describe well the experimental HmE data for present system except for ethanol + DIPE in case of FTB model. FTB model also predicted the excess molar volume (VmE) for the present systems and compared well with their reported excess volume data.