Excess molar enthalpies of ternary mixtures containing o-toluidine + tetrahydropyran with pyridine or isomeric picolines or benzene or toluene at 308.15 K

Excess molar enthalpies, image of o-toluidine (i) + tetrahydropyran (j) + pyridine or α- or β- or γ-picoline or benzene or toluene (k) ternary mixtures have been measured over entire mole fraction at 308.15 K using 2-drop calorimeter. The experimental data have been fitted to Redlich–Kister equation to evaluate ternary parameters along with their standard deviations. The image values for the studied mixtures except those of o-toluidine (i) + tetrahydropyran (j) + toluene (k) are negative over entire composition range. The topology of the constituents of the mixtures has been utilized to (Graph theory) predict image values of the investigated mixtures. The observed data have also been analyzed in terms of Prigogine–Flory–Patterson theory, It has been observed that image values predicted by Graph theory compare well with their corresponding experimental values.