Ultrasonic and dielectric behaviour of binary systems of methyl ethyl ketone with 1,2-dichloroethane, methylene chloride, trichloroethene, tetrachloroethene and cyclohexane

Abstract

Measurements of ultrasonic velocity, u, and isentropic compressibilities, k_s, have been made for binary mixtures of methyl ethyl ketone (MEK) with 1,2-dichloroethane (CH₂ClCH₂Cl), trichloroethene (CHClCCl₂) and tetrachloroethene (CCl₂CCl₂) at 303.15 and 313.15 K, for mixtures of MEK with methylene chloride (CH₂Cl₂) at 293.15 and 303.15 K, and for mixtures of MEK with cyclohexane (c-C₆H₁₂) at 303.15 K. Measurements of relative permittivities, ε, and refractive indices, n, have also been made for binary mixtures of MEK with CH₂Cl₂, CH₂ClCH₂Cl, CHClCCl₂, CCl₂CCl₂ and c-C₆H₁₂ at 303.15 K. The quantities Δk_s and Δε which refer, respectively, to the deviations of the isentropic compressibilities and relative permittivities of the mixtures from the values arising from the mole fraction mixture law, have been calculated. Δk_s is positive for mixtures of MEK with c-C₆H₁₂ and CH₂Cl₂, and negative for mixtures of MEK with CH₂ClCH₂Cl, CHClCCl₂, and CCl₂CCl₂, whereas Δε is positive for mixtures of MEK with CH₂Cl₂, CH₂ClCH₂Cl and CHClCCl₂, and negative for its mixtures with CCl₂CCl₂ and c-C₆H₁₂. Δg refers to the deviations of the values of the Kirkwood correlation parameter, g, for mixtures from the values arising from the mole fraction mixture law (as calculated from the data for ε and n for mixtures of MEK with CH₂ClCH₂Cl and CH₂Cl₂); values of Δg have been found to be positive. The values of Δk_s, Δε and Δg for the various systems show that MEK forms molecular complexes with CH₂Cl₂, CH₂ClCH₂Cl, CHClCCl₂ and CCl₂CCl₂. The values of the equilibrium constant K_f for the formation of 1:1 complexes of MEK with CH₂ClCH₂Cl and CH₂Cl₂, as calculated using the relative permittivities, are in accord with the theory of Barriol and Weisbecker. The values of the dipole moments of MEK in CCl₂CCl₂ and c-C₆H₁₂ also indicate a specific interaction of MEK with CCl₂CCl₂.