Thermophysical properties of the binary mixtures diethyl carbonate plus (n-dodecane or n-tetradecane) at several temperatures

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 rt-tetradecane wer e measured at atmospheric pressure, over the entire composition range. Thes e results are used to calculate molar volumes, isentropic and isothermal co mpressibilities, isobaric thermal expansivities, and isobaric and isochoric molar heat capacities as well as the corresponding excess quantities. Posi tive values and a parabolic composition dependence were found for all exces s quantities except for the excess molar heat capacities, which take negati ve values and are W-shaped. Excess molar volumes increase with both alkyl c hain length of the n-alkane and temperature. Excess isobaric molar heat cap acities decrease as the size of the n-alkane increases and exhibit differen t temperature dependences with mole fraction. All other properties, with th e exception of the excess isochoric molar heat capacity, show similar behav ior for both mixtures.