Experimental and Predicted Densities and Refractive Indices of the Ternary Mixtures (Glycerol + Water + Methanol), (Glycerol + Water + Ethanol) and (Glycerol + Water + 2-Propanol) at Different Temperatures and Ambient Pressure

Densities and refractive indices of the three following ternary mixtures (glycerol + water + methanol), (glycerol + water + ethanol) or (glycerol + water + 2-propanol) and the corresponding binary mixtures were measured over the entire composition range at three temperatures from 298.15 to 318.15 K and atmospheric pressure. Excess molar volumes,V₁₂₃^E, and changes of refractive index on mixing,Δn_D,123, for the ternary systems were calculated and compared with the results obtained with some semi-empirical methods for the estimation of ternary properties from binary results. Furthermore, Perturbed Chain Statistical Associating Fluid Theory was applied to model the density for the binary and ternary mixtures. On the other hand, four mixing rules (Lorentz–Lorenz, Gladstone–Dale, Laplace, and Eykman) were used to compute predictively the refractive index of the mixtures. The fitting parameters of all equations and their respective standard deviations are reported and the results are discussed in terms of molecular interactions.