Excess molar volumes and excess isentropic compressibilities of o-toluidine + tetrahydropyran with pyridine or benzene or toluene ternary mixtures at 298.15, 303.15 and 308.15 K

摘要

The densities, ρ _(123), and speeds of sound, u _(123), of ternary o-toluidine (OT, 1) + tetrahydropyran (THP, 2) + pyridine (Py) or benzene or toluene (3) mixtures have been measured as a function of composition at 298.15, 303.15 and 308.15 K. Values of the excess molar volumes, V _(123) ~E and excess isentropic compressibilities, (κ_S ~E)_(123) of the studied mixtures have been determined by employing the measured experimental data. The observed thermodynamic properties were fitted with the Redlich-Kister equation to determine adjustable ternary parameters and standard deviations. The V _(123) ~E and (κ_S ~E)_(123) values were also analyzed in terms of Graph theory. It was observed that Graph theory correctly predicts the sign as well as magnitude of V_(123) ~E and (κ_S ~E)_(123) values of the investigated mixtures. Analysis of the data suggests strong interactions and a more close packed arrangement in OT (1) + THP (2) + Py (3) mixtures as compared to those of the OT (1) + THP (2) + benzene (3) or toluene (3) mixtures. This may be due to the presence of a nitrogen atom in Py which results in stronger interactions for the OT:THP molecular entity as compared to those with benzene or toluene.