Vapour-liquid equilibria in binary mixtures of some chloroalkanes + 2-butanone

摘要

The paper presents the isothermal VLE data of 1,1,1-trichloroethane and 1,1,2,2-tetrachloroethane + 2-butanone systems within the temperature range 298.15K-318.15K obtained by a static method. The mixtures were prepared by weight and degassed directly into the equilibrium cell. The vapour pressures vs. liquid phase composition data have been used to calculate the activity coefficients of the two components, and the excess malar Gibbs energies, G~E, for the mixtures, using Barker's method. For excess Gibbs energy, G~E, Redlieh-Kister, Wilson and NRTL equations were used and the vapour phase imperfection was taken in the terms of the 2-nd virial coefficients. The 1,1,1-trichloroethane + 2-butanone mixture shows positive deviations (G~E >0), while the 1,1,2,2-tetrachloroethane + 2-butanone system exhibits negative deviations (G~E <0). For both systems G~E values increase with increasing temperature. The equimolar excess enthalpies, H~E (x - 0.5), estimated from the temperature dependence of G~E(x - 0.5) are in agreement as sign and magnitude with the calorimetric literature values.