Thermophysical Properties of the Binary Mixtures Diethyl Carbonate + (<i>n</i>-Dodecane or <i>n</i>-Tetradecane) at Several Temperatures

Abstract

The density and the speed of sound at (288.15, 293.15, 298.15, and 308.15) K and the isobaric molar heat capacity at (288.15, 298.15, and 308.15) K of binary mixtures of diethyl carbonate with n-dodecane or n-tetradecane were measured at atmospheric pressure, over the entire composition range. These results are used to calculate molar volumes, isentropic and isothermal compressibilities, isobaric thermal expansivities, and isobaric and isochoric molar heat capacities as well as the corresponding excess quantities. Positive values and a parabolic composition dependence were found for all excess quantities except for the excess molar heat capacities, which take negative values and are W-shaped. Excess molar volumes increase with both alkyl chain length of the n-alkane and temperature. Excess isobaric molar heat capacities decrease as the size of the n-alkane increases and exhibit different temperature dependences with mole fraction. All other properties, with the exception of the excess isochoric molar heat capacity, show similar behavior for both mixtures.