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1

Volumetric, Optical, Acoustical and Viscometric Study of Molecular Association in Binary Mixtures of Butylamine with 1-Butanol and Tert-Butanol

100%

Singh S., Parveen S., Shukla D., Gupta M., Shukla J.

Acta Physica Polonica A

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2007

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vol. 111

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issue 6

847-858

EN

Density (ρ), refractive index (n), ultrasonic velocity (u), and viscosity (η) were measured for the binary mixtures formed by butylamine with 1-butanol and tert-butanol at temperatures 293, 303, and 313 K over the entire composition range. Excess molar volume V_m^E, molar refraction deviation ΔR_m, deviation in ultrasonic velocity Δu, viscosity deviation Δη, and excess Gibb's free energy of activation for viscous flow ΔG^{*E} were derived from the experimental data and the computed results were fitted to the Redlich-Kister polynomial equation. The values of V_m^E, ΔR_m, Δu, Δη, and ΔG^{*E} were plotted against the mole fraction of butylamine. The observed positive and negative values of excess parameters for both the mixtures were explained on the basis of intermolecular interactions present in these mixtures. The higher negative values of V_m^E and ΔR_m and positive values of Δu, Δη, and ΔG^{*E} for butylamine + 1-butanol mixture suggest that specific interactions are taking place in butylamine + 1-butanol mixture, while weak dipole-dipole induced forces and dispersive forces seem to be responsible for butylamine + tert-butanol mixture. Furthermore, different empirical relations were used to correlate the binary refractive indices. An excellent agreement was found between experimental and theoretical values.

2

Thermoacoustical Excess Properties of Binary Liquid Mixtures - A Comparative Experimental and Theoretical Study

100%

Yasmin M., Singh K., Parveen S., Gupta M., Shukla J.

Acta Physica Polonica A

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2009

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vol. 115

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issue 5

890-900

EN

Specific heat ratio (γ), pseudo-Grüneisen parameter (Γ), heat capacity (C_p) and effective Debye temperature (θ_{D}) for binary system of tetrahydrofuran with o-cresol and methanol respectively, were calculated using the experimentally measured densities, velocities and viscosities of the pure liquids and their mixtures over the whole composition range and at T = 293, 303, 313 K. The excess pseudo-Grüneisen parameter (Γ ^{E}), excess molar isentropic compressibility (K_{s}^{E}) and excess acoustic impedance (Z^{E}) were also calculated. The excess deviation functions have been correlated using Redlich-Kister polynomial equation. The observed values of the excess parameters plotted against the mole fraction of tetrahydrofuran have been explained on the basis of intermolecular interaction suggesting strong interaction in tetrahydrofuran + o-cresol than in tetrahydrofuran + methanol. Partial molar isentropic compressibility at infinite dilution and their excess values were calculated for each component. Sanchez theory, Goldsach-Sarvas volume fraction statistics, Sudgen's relation, Flory-Patterson-Rastogi and Brock and Bird model were used with the Aurebach relation to compute theoretically the values of ultrasonic velocities at varying temperatures. The velocity deviations were estimated in terms of average percentage deviations. Internal pressure for both the systems were calculated theoretically and discussed on the basis of relative applicability of the models in theoretical estimations. The isothermal compressibility (k_T), for these binary mixtures were theoretically evaluated by using the Flory statistical theory and five hard sphere models and compared with the experimental values.

3

Molecular Interaction Study of Binary Mixtures of THF with Methanol and o-Cresol - an Optical and Ultrasonic Study

86%

Parveen S., Singh S., Shukla D., Singh K., Gupta M., Shukla J.

Acta Physica Polonica A

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2009

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vol. 116

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issue 6

1011-1017

EN

The refractive indices, densities and ultrasonic velocities of binary liquid mixtures of tetrahydrofuran (THF) with methanol and o-cresol over the entire composition range have been measured at 293, 303 and 313 K. Refractive index, density and ultrasonic velocity data have been used to evaluate the molar refraction deviation ΔR_{m}, deviation in ultrasonic velocity Δu, excess internal pressure π_{i}^{E}, excess molar enthalpy H_{m}^{E} and excess free volume V_{f}^{E}. The computed results of ΔR_{m}, Δu, π_{i}^{E}, H_{m}^{E} and V_{f}^{E} were fitted to the Redlich-Kister polynomial equation. These results suggest that specific strong interactions are taking place in THF + o-cresol mixture while dispersive forces seem to be responsible for behaviour of THF + methanol mixture. Further, experimental refractive index and density data of these mixtures were also used to test the validity of the empirical/semi-empirical relations and models for refractive index and density, respectively.

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3 Acta Physica Polonica A

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1 Yasmin M.

Volumetric, Optical, Acoustical and Viscometric Study of Molecular Association in Binary Mixtures of Butylamine with 1-Butanol and Tert-Butanol

Thermoacoustical Excess Properties of Binary Liquid Mixtures - A Comparative Experimental and Theoretical Study

Molecular Interaction Study of Binary Mixtures of THF with Methanol and o-Cresol - an Optical and Ultrasonic Study