Excess Gibbs energies and excess enthalpies of liquid binary mixtures containing nitroalkanes

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Abstract Marongiu, B., Monaci, R. and Porcedda, S., 1993. Excess Gibbs energies and excess enthalpies of liquid binary mixtures containing nitroalkanes. Fluid Phase Equilibria , 84:281-296. A head-space gas Chromatographie technique was used to determine vapour phase equilibria for binary mixtures of 1-nitroalkanes (1-nitropropane, 1-nitrobutane, 1-nitropentane) + n -heptane or cyclohexane. Excess molar Gibbs energies, G E , for the mixtures investigated were obtained. All systems exhibit positive deviations. The G E values decrease with increasing nitroalkane chain length. Activity coefficients at infinite dilution, γ ∞ t , were also evaluated. A flow microcalorimeter, Model 2277-LK.B, was used to determine excess enthalpies, H E , as a function of concentration at atmospheric pressure and 298.15 K, for binary liquid mixtures containing the same 1-nitroalkanes with tetrachloromethane. A tentative approach, based on an additivity scheme of surface interactions combined with the scaled particle theory, is presented to estimate and analyse group contributions to Δ G solv 0 and Δ H solv 0 , the energy and the enthalpy of solvation respectively.