Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

In this work, densities, q and refractive indices, nD of N-Methylcyclohexylamine + 2-alkanols have been measured over the entire range of composition at four temperatures 298.15, 308.15, 318.15 and 328.15 K and ambient pressure (81.5 kPa), using Anton Paar DMA 4500 oscillating densimeter and Anton Paar Abbemat 500 automatic refractometer. From experimental data, excess molar volumes, VE m, partial molar volumes, Vi , apparent molar volumes, V/i , thermal expansion coefficients, a, excess thermal expansion coefficients, aE, isothermal coefficients of excess molar enthalpy, oHE m=PP T;x, and refractive index deviations, DnD, have been calculated for binary systems consisting of NMethylcyclohexylamine + 2-alkanols (2-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol and 2-octanol). The excess molar volumes, VE m, and refractive index deviations, DnD were correlated with the Redlich Kister polynomial equation. The effect of temperature and chain length of alcohol on the excess molar volumes and refractive index deviations are discussed in terms of molecular interaction between unlike molecules. The excess molar volumes were negative and refractive index deviations were positive over the entire composition range and were plotted against the mole fraction of 2-alkanols over the entire composition range. Negative excess molar volumes and positive refractive index deviations indicate the strong hydrogen bonding between unlike molecules of mixtures. A comparative study has been made of the refractive indices obtained experimentally and those calculated by means of the Lorentz Lorenz, Gladstone Dale, Weiner and Arago Biot relations.