Thermodynamic behaviour of binary systems of quinoline with methylene chloride, chloroform, carbon tetrachloride, benzene and cyclohexane. Vapour pressures and excess molar Gibbs energies

Abstract

Measurements of vapour pressures have been made using a static method for the binary systems of quinoline (C₉H₇N) with chloroform (CHCl₃), methylene chloride (CH₂Cl₂), carbon tetrachloride (CCl₄), benzene (C₆H₆) and cyclohexane (c-C₆H₁₂) at 293.15 K. The total pressure vs. liquid phase composition data have been used to calculate for the various systems, the activity coefficients γ_A and γ_B of C₉H₇N (A) and the other component (B) and the excess molar Gibbs energies, G^E_m, by using Barker's procedure. G^E_m is found to be highly positive for C₉H₇N–c-C₆H₁₂, slightly positive for C₉H₇N–CCl₄ and C₉H₇N–C₆H₆, and negative for C₉H₇N–CHCl₃ and C₉H₇N–CH₂Cl₂. G^E_m data at x_A= 0.5 for the various systems have been used to estimate K_f, the equilibrium constant for the formation of the 1 : 1 (AB) complex, using Saroléa-Mathot's theory of associated solutions. G^E_m and K_f data show that C₉H₇N forms tight complexes with CHCl₃ and CH₂Cl₂ owing to strong intermolecular association in the liquid state, and that it forms weak complexes with CCl₄ and C₆H₆.