Densities and speeds of sound for the binary mixtures acetone, 2-butanone and 2-pentanone + diethyl carbonate, over the whole composition range, at T = 298.15 K and atmospheric pressure have been measured. Excess molar volumes and deviations in isentropic compressibility for the binary systems were fitted to the Redlich-Kister polynomial. Isobaric vapor-liquid equilibria for the binary systems acetone + diethyl carbonate, 2-butanone + diethyl carbonate and 2-pentanone + diethyl carbonate at P = 101.3 kPa have been determined. The activity coefficients were calculated to be thermodynamically consistent and they were correlated with the Wilson, NRTL, UNIQUAC and Redlich-Kister equations. Interaction parameters related to the carbonate (-OCOO-) and ketone (-CO-) groups, in ASOG and UNIFAC methods, have been determined using our experimental VLE data. (c) 2005 Elsevier B.V. All rights reserved.