Excess molar volumes, V E, excess molar enthalpies, H E, speeds of sound, u, and vapor-liquid equilibrium data of 1,4-dioxane (1) + aniline or N-methyl aniline or o-toluidine (2) binary mixtures have been measured as a function of composition at 308.15 K. Isentropic compressibility changes that occur for mixing, $\kappa_{S}^{\mathrm{E}}$ , and excess Gibb’s energies, G E, have been determined by employing speeds of sound and vapor-liquid equilibrium data. The $V^{\mathrm{E}}, H^{\mathrm{E}},\kappa_{S}^{\mathrm{E}}$ and G E values have been estimated by (i) graph theory and (ii) the Prigonone-Flory-Patterson theory (PFP). It was observed that values of $V^{\mathrm{E}}, H^{\mathrm{E}},\kappa_{S}^{\mathrm{E}}$ and G E predicted by graph theory compare well, relative to the PFP theory, with their corresponding experimental values.