Binary systems of acetone with tetrachloroethylene, trichloroethylene, methylene chloride, 1,2-dichloroethane and cyclohexane. Part 3.—Dielectric properties and refractive indices at 303.15 K

Abstract

Measurements of dielectric constants, ε, and refractive indices, n, have been made for binary liquid mixtures of acetone with tetrachloroethylene (CCl₂CCl₂), trichloroethylene (CHCĺCCl₂), methylene chloride (CH₂Cl₂), 1,2-dichloroethane (CH₂ClCH₂Cl) and cyclohexane (c-C₆H₁₂) at 303.15 K. Values of the quantity Δε, which refers to the deviations of experimental values of the dielectric constants of the mixtures from values arising from the law of the ideal-volume-fraction mixtures, have been calculated. The positive values of Δε for acetone + CH₂ClCH₂Cl and acetone + CH₂Cl₂ and very slightly negative values of Δε for acetone + CHClCCl₂ are attributed to the formation of molecular complexes of acetone with CH₂ClCH₂Cl, CH₂Cl₂ and CHClCCl₂. The values of the equilibrium constant, K_f, for the formation of 1:1 complexes of acetone with CH₂ClCH₂Cl, CH₂Cl₂ and CHClCCl₂ have also been calculated, using the dielectric-constant data. The values of the apparent dipole moments µ_app of acetone at various mole fractions in the solvents c-C₆H₁₂ and CCl₂CCl₂ have also been calculated. The values of µ²_app suggest that there exists a specific interaction between acetone and CCl₂CCl₂.