Ultrasonic, dielectric and viscometric behaviour of binary systems of 1,4-dioxane with 1,2-dichloroethane, methylene chloride, trichloroethene, tetrachloroethene and cyclohexane

Abstract

Ultrasonic velocities, u, and isentropic compressiblities, k_s, have been measured for mixtures of 1,4-dioxane with 1,2-dichloroethane (CH₂ClCH₂Cl) and trichloroethene (CHClCCl₂) at 298.15 and 308 15 K, for mixtures of 1,4-dioxane with methylene chloride (CH₂Cl₂) and tetrachloroethene (CCl₂CCl₂) at 293.15 and 303.15 K, and for 1,4-dioxane–cyclohexane (c-C₆H₁₂) at 308.15 K. Relative permittivities, ε, and refractive indices, n, have been measured for mixtures of 1,4-dioxane with CH₂ClCH₂Cl, CHClCCl₂, CCl₂CCl₂ and c-C₆H₁₂ at 308.15 K, and for 1,4-dioxane–CH₂Cl₂ at 303.15 K. Also the dynamic viscosities, η, have been measured for these mixtures at 303.15 K. The relative-permittivity data have been used to calculate total molar polarisations, P, for the various systems. The quantities Δk_s and ΔP which refer, respectively, to the deviations of the isentropic compressibilities and total polarisations of the mixtures from the values arising from the mole-fraction mixture law, have been calculated. The apparent molar polarisations, P_A, of CH₂ClCH₂Cl, CH₂Cl₂, CHClCCl₂, CCl₂CCl₂ and c-C₆H₁₂ have also been calculated in 1,4-dioxane. The viscosity data for mixtures have been used to calculate the parameter d which is regarded as a measure of strength of interaction between the components. The values of Δk_s, d, ΔP and P_A show that 1,4-dioxane forms strong intermolecular complexes with CH₂ClCH₂Cl and CH₂Cl₂, and weak complexes with CHClCCl₂. The values of the equilibrium constant, K_f, for the formation of 1 : 1 complexes of 1,4–dioxane with CH₂ClCH₂Cl, CH₂Cl₂ and CHClCCl₂, as calculated using relative permittivities, are in accord with the theory of Barriol and Weisbecker.