Excess enthalpies of binary mixtures of 2-ethoxyethanol with four hydrocarbons at 298.15, 308.15, and 318.15 K - An experimental and theoretical study

New experimental data are reported for the thermodynamic investigation of the intermolecular and intra-molecular hydrogen bonding in 2-ethoxyethanol + hydrocarbons. The excess enthalpies of the mixtures of 2-ethoxyethanol + n-hexane, or cyclohexane, or benzene, or n-octane at three temperatures (298.15, 308.15, and 318.15 K) were measured. The data are correlated with the statistical thermodynamic model non-random hydrogen bonding (NRHB) which accounts for both types of hydrogen bonds and was recently developed by the authors. A single set of hydrogen bonding parameters is used for all the alkoxyethanol systems and for the recently calculated thermodynamic properties. The results showed a satisfactory agreement between experimental and calculated data and the contributions of all different types of molecular interactions were calculated. The intra-molecular hydrogen bonding contribution to the heats of mixing is exothermic and significant. The calorimetric measurements are combined with dielectric ones and the derived Kirkwood factor is used to interpret the physicochemical behaviour of our systems. (c) 2006 Elsevier B.V. All rights reserved.