Entropy and Enthalpy variations with Acoustic parameters of Cholesteryl oleyl carbonate

The ultrasonic velocity (U), density (ρ), viscosity (η) have been measured for Cholesteryl oleyl carbonate at different temperatures. From the experimental data, , Free Volume (VF)), Internal Pressure (πi), Relaxation time (τ), Gibbs Free Energy (ΔG), Absorption Coefficient () and Enthalpy (H), Entropy(S) have been calculated.Entropy is a thermodynamic state property, its value depends only on the state of a system, not on the history of the system. Therefore, to determine the change in entropy of a system from one state to another, it is sufficient to evaluate the change for a reversible process between those two states; the change in entropy for any other process connecting the same two states will be the same as the change for the reversible process The properties have been used to discuss the presence of significant interactions between the component molecules.