Molar excess volumes and excess isentropic compressibilities of ternary mixtures containing o-toluidine

摘要

Molar excess volumes, V-ijk(E), and speeds of sound, U-ijk, of o-toluidine ( 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. The observed speed of sound data have been utilized to determine the excess isentropic compressibilities, ( K-S(E))(ijk), of the ternary ( i + j + k) mixtures. The Moelywn-Huggins concept ( Huggins in Polymer 12: 389-399, 1971) of connectivity between the surfaces of the binary mixture constituents has been extended to ternary mixtures ( using the concept of a connectivity parameter of third degree of molecules, (3)xi, which in turn depends on its topology) to obtain an expression that describes well the measured V-ijk(E) and ( K-S(E))(ijk) data. The observed data have also been analyzed in terms of Flory's theory.