Theoretical estimations of thermodynamic properties of liquid mixtures by Flory's statistical theory

Abstract

Flory's statistical theory has been employed for the computation of ultrasonic velocity (u), density (ρ), internal pressure (P _i), thermal expansion coefficient (α), isothermal compressibility (β _T), adiabatic compressibility (β _S), heat capacity at constant pressure (C _P), heat capacity at constant volume (C _V), heat capacities ratio (γ), pseudo-Gruneisen parameter (Γ), excess volume (V ^E) and excess heat capacity at constant pressure () at varying temperatures for 10 binary and 5 ternary systems. The binary systems under investigation are: acetonitrile + benzene, benzene + DMF, acetonitrile + DMF, cyclohexanol + cyclohexane, piperidine + tetrahydropyran, piperidine + cyclohexane, tetrahydropyran + cyclohexane, benzene + p-xylene, benzene + p-dioxan, acetone + methyliodide, and the ternary systems are: benzene + chloroform + cyclohexane, toluene + chloroform + cyclohexane, chlorobenzene + chloroform + cyclohexane, dioxane + chloroform + cyclohexane and chlorobenzene + cyclohexane + n-heptane. The results of calculations show that for all the systems under consideration, the calculated values of various thermodynamic parameters show the same trend as observed experimentally. Fairly good agreement is found between theoretical and experimental values. The ultrasonic velocity of liquid mixtures is obtained using the most popular Flory theory without the help of any empirical relation.

Keywords:

• Flory's statistical theory
• Ultrasonic velocity
• Thermal expansivity
• Isothermal compressibility

Acknowledgements

The author, J. D. Pandey is thankful to UGC, New Delhi, India, for the award of Emeritus Fellowship and V. Sanguri is grateful to C.S.I.R., New Delhi, India for providing financial assistance.