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, ks, 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, Iµ, 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 Δks and ΔIµ 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. Δks is positive for mixtures of MEK with c-C6H12 and CH2Cl2, and negative for mixtures of MEK with CH2ClCH2Cl, CHClCCl2, and CCl2CCl2, whereas ΔIµ 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 Iµ and n for mixtures of MEK with CH2ClCH2Cl and CH2Cl2); values of Δg have been found to be positive. The values of Δks, ΔIµ and Δg for the various systems show that MEK forms molecular complexes with CH2Cl2, CH2ClCH2Cl, CHClCCl2 and CCl2CCl2. The values of the equilibrium constant Kf 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.