Excess quantities of dialkyl carbonate + cyclohexane mixtures at a variable temperature

Abstract

The density at 288.15, 293.15, 298.15 and 308.15 K, sound speed at 298.15 K, and isobaric molar heat capacity at 288.15, 298.15 and 308.15 K, of binary mixtures of cyclohexane with dimethyl carbonate or diethyl carbonate at atmospheric pressure were measured throughout the composition range. The data were used to calculate the excess quantities for the following properties: molar volumes, isentropic and isothermal compressibilities, isobaric thermal expansivity, and isobaric and isochoric molar heat capacities. As a rule, these excess quantities were substantially greater for the mixtures containing dimethyl carbonate than for those of diethyl carbonate. The excess isobaric molar heat capacity of both mixtures was found to exhibit a W-shaped variation with composition. Unlike its variation with the excess volumes, changes in this quantity as a function of temperature are non-linear.