Relationship between molecular constant, Grüneisen and nonlinearity parameters and intermolecular volume expansivity of liquids using thermo-acoustic data

Abstract

Relationships among various parameters describing the anharmonic, thermo-acoustic, and nonlinear properties of liquids are developed. The microscopic Gruneisen parameter, Beyer's nonlinearity parameter, fractional available volume, repulsive exponent of intermolecular potential, isochoric temperature derivative of sound velocity, the isothermal volume derivatives of isochoric heat capacity and thermodynamic Gruneisen parameter are shown to be related to the molecular constant representing the ratio of internal pressure to cohesive pressure of liquids. The contributions of intermolecular vibrations to heat capacity and volume expansivity are evaluated from the relationship between the microscopic and thermodynamic Gruneisen parameters using thermo-acoustic data for liquids. The calculated values of various parameters are reasonably satisfactory and explain the experimental results on sound propagation data of liquids. The results are used to develop further understanding of the Gruneisen parameter, fractional available volume, molecular constant, repulsive exponent of intermolecular potential, and intermolecular volume expansivity in describing various thermo-acoustic and nonlinear properties and the anharmonic behaviour with regard to molecular order and intermolecular interactions in liquids.