Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

Densities were experimentally determined in the whole range of composition at T = 298.15 K for the ternary system {methylcyclohexane (1) + cyclohexane (2) + n-alkanes (3)} and for the seven corresponding binary systems. The n-alkanes include n-hexane, nheptane, and n-octane. Excess molar volumes, VE, were calculated for the binaries and ternaries systems. The V E 123 data are positive over the entire range of composition for the systems {methylcyclohexane (1) + cyclohexane (2) + n-heptane (3) or n-octane (3)} at three fixed compositions (fm = X1/X2). For the system {methylcyclohexane (1) + cyclohexane (2) + n-hexane (3)}, the VE values showed positive for fm = 0.3 and negative for fm = 3. The VE data exhibit, an inversion in sign in the mixture containing fm = 1 for later ternary system. Several empirical expressions are used to predict and correlate the ternary excess molar volumes from experimental results on the constituted binaries and analyzed to gain insight about liquid mixture interactions.