Excess molar volumes and excess isentropic compressibilities of tetrahydropyran + benzene + cyclo or n-alkanes ternary mixtures at 308.15 K

Excess molar volumes, image, speeds of sound, uijk, of tetrahydropyran (i) + benzene (j) + cyclohexane or n-hexane or n-heptane (k) ternary mixtures have been measured as a function of composition at 308.15 K and atmospheric pressure. The observed speeds of sound data of the investigated ternary mixtures have been utilized to calculate their excess isentropic compressibilities, image. The image and image have been fitted to the Redlich–Kister equation to calculate ternary adjustable parameters and standard deviations. Connectivity parameters of third degree of the constituents of mixtures (which in turn depends on the topology of a molecule) have been employed to determine excess molar volumes, image, and excess isentropic compressibilities, image. It has been observed that image and image values calculated by the Graph theory (which involves connectivity parameter of third degree of a molecule) compare well with their corresponding experimental values.