Thermodynamic functions of activation for viscous flow of cholesterol in some non-aqueous solutions

Abstract

The viscosities of solutions of cholesterol in benzene, toluene, carbon tetrachloride, chloroform and 1,2-dichloroethane up to 0.4 mol kg −1 at 293, 298, 303, 313, 323 and 333 K have been measured. On the basis of Eyring's theory of rate processes, the molar thermodynamic functions of activation for viscous flow of solution, i.e. the molar Gibbs free energy Δ# Ḡ 1,2, molar enthalpy, Δ# H̄ H̄ 1,2 and molar entropy, Δ# S̄ 1,2, and corresponding partial molar quantities of activation for viscous flow of solute and solvent have been determined. Additionally, the viscosity coefficients B and D and their temperature derivatives are calculated and correlated with solvent dielectric parameter β. The influence of the “solvent effect” on the above parameters is discussed on the basis of Eyring's theory of the transition state and the structure of solution.