Dinesh Chand

Volumetric, ultrasonic and viscometric studies of molecular interactions in binary mixtures of aromatic+aliphatic alcohols at different temperatures

The densities, ρ, ultrasonic speeds, u and viscosities,u2009ηu2009of pure benzyl alcohol, 1-propanol, 2-propanol and those of their binary mixtures, with benzyl alcohol as a common component, have been measured at 298.15, 303.15, 308.15 and 313.15u2009K over the entire composition range. The excess molar volume, V E, deviation in isentropic compressibility, Δk s , excess thermal expansivity, αE, deviations in ultrasonic speed, Δu and viscosity, Δη, partial molar volume and compressibility, and of 1-propanol/2-propanol in benzyl alcohol at infinite dilution have been evaluated from the experimental data. The results have been used to discuss the nature and strength of intermolecular interactions in these mixtures. The V E values have also been calculated theoretically by using the Florys statistical theory and Prigogine–Flory–Patterson theory. The calculated V E values were found in good agreement with the experimental V E values. The thermal expansivity,u2009αu2009and isothermal compressibility, k T have been calculated theoretically by using Florys theory and various hard sphere models, and were compared with experimentalu2009αu2009and k T values.

Ultrasonic, volumetric and viscometric studies of molecular interactions in binary mixtures of dimethylsulphoxide with polar substituted cyclohexanes at 30°C

The densities, ρ, ultrasonic speeds, u and viscosities, η of binary mixtures of dimethylsulphoxide (DMSO) with cyclohexanol, cyclohexanone and cyclohexylamine, with DMSO as a common component, over the whole composition range expressed by mole fraction of DMSO, including those of pure liquids have been measured at 30°C. By using the experimental values of ρ, u and η, the deviations in isentropic compressibility, Δk s, excess intermolecular free length, , excess molar volume, V E, deviations in viscosity, Δη, excess free energy of activation of viscous flow, G*E, partial molar compressibility and volume, and respectively of cyclohexanol/cyclohexanone/cyclohexylamine in DMSO at infinite dilution have been calculated. The variations of these parameters with composition of the mixture suggest that the strength of interactions in these mixtures follow the order: cyclohexanolu2009<u2009cyclohexanoneu2009<u2009cyclohexylamine. The isothermal compressibility, kT for these binary mixtures has been theoretically calculated by using the Florys statistical theory and five hard sphere models and the results were compared with the experimental kT values. Further, the viscosities of these binary mixtures were theoretically predicted on the basis of various relations by using the experimental values of pure components and the results were compared with the experimental findings.

Excess internal pressures, excess free volumes and excess thermodynamic parameters of some non-aqueous binary mixtures from ultrasonic speed, density and viscosity data

The internal pressure, πi; free volume, V f; excess internal pressure, ; excess free volume, ; excess free energy, G E; excess enthalpy, H E and excess entropy, S E of mixing for the binary mixtures of tetrahydorfuran (THF) with benzene, toluene, o-xylene, m-xylene, p-xylene and mesitylene have been calculated from experimental ultrasonic speed, density and viscosity data over the whole composition range at 298.15 K. The results have been discussed in terms of intermolecular interactions between the component molecules in the mixture. The variations of these excess functions with composition indicate that the THF-aromatic hydrocarbon interaction in these mixtures follows the order: benzene > toluene > p-xylene > m-xylene > o-xylene > mesitylene. Further, πi of these binary mixtures are also evaluated theoretically by using various equations proposed in the literature. The results are compared with the experimental findings, and relative merits of these equations in predicting internal pressure are discussed.