Topological investigations of binary and ternary mixtures: excess isentropic compressibilities

Abstract

The speed of sound, U ij 1,3-dioxolane (D) in binary mixtures ( ij) with benzene, cyclohexane, n-hexane or n-heptane and U ijk for 1,3-dioxolane in ternary mixtures ( ijk) with the same hydrocarbons have been measured as a function of composition at 298.15 K. The observed data have been utilised to evaluate excess isentropic compressibility of binary, ( κ s E) ij and ternary ( κ s E) ijk mixtures using density and speed of sound values of the binary and ternary mixtures. The Moelyn-Huggins concept of interaction between the molecular surfaces of the components of a binary mixture [Polymer 12 (1971) 389] has been extended to evaluate excess isentropic compressibility of the studied binary and ternary mixtures. It has been observed that κ s E values predicted by a graph–theoretical approach using connectivities of third degree for binary mixtures compare reasonably well with their corresponding experimental values and κ s E for ternary mixtures are of the same sign and order of magnitude.