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

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 binar y mixtures of cyclohexane with dimethyl carbonate or diethyl carbonate at a tmospheric pressure were measured throughout the composition range. The dat a were used to calculate the excess quantities for the following properties : molar volumes, isentropic and isothermal compressibilities, isobaric ther mal expansivity, and isobaric and isochoric molar heat capacities. As a rul e, these excess quantities were substantially greater for the mixtures cont aining dimethyl carbonate than for those of diethyl carbonate. The excess i sobaric molar heat capacity of both mixtures was found to exhibit a W-shape d variation with composition. Unlike its variation with the excess volumes, changes in this quantity as a function of temperature are non-linear. (C) 2001 Elsevier Science B.V. All rights reserved.