Thermodynamic Excess Properties for the Ternary Benzene + n-Heptane + n-Octane System at Temperatures of 298.15–318.15 K: Measurement and Correlation

Abstract

The density (ρ), speed of sound (u), and refractive indices (nD) data at atmospheric pressure for benzene + n-heptane + n-octane mixtures from 298.15 to 318.15 K have been measured. The data were further used to derive excess molar volume (VmE) and deviation in u (Δu) and nD (Δn). The VmE values for the ternary mixtures were positive and predicted from the constituent binary data using various fitting equations, geometrical solution models, and the Prigogine–Flory–Patterson theory. The u data at 298.15 K were analyzed by Schaaff’s collision factor theory and Nomoto correlations. Using the Jacobson free length theory, LfE and VaE were also calculated. The nD data for these mixtures were also predicted from the pure component data.