The molar heat capacity of the azeotropic mixture composed of 0.329 water, 0.397 ethanol, and 0:274 toluene. was measured by adiabatic calorimetry in the temperature range 79-320 K. The glass transition and phase transitions of the mixture were determined from the curve of the heat capacity with respect to temperature. The glass transition occurred at (108.4 +/- 0.2) K. The phase transitions took place in the temperature range of 129-155 K corresponding to the solid-solid and solid-liquid phase transitions of ethanol. water and toluene. respectively. The thermodynamic functions and the excess thermodynamic functions of the mixture relative to standard temperature 298.15 K were derived from the relationships of the thermodynamic functions and the function of the measured heat capacity with respect to temperature. (C) 2004 Elsevier B.V. All rights reserved.