Heat capacities of aqueous solutions of acetone;: 2,5-hexanedione;: Diethyl ether;: 1,2-dimethoxyethane;: Benzyl alcohol;: and cyclohexanol at temperatures to 523 K

The heat capacities of aqueous solutions of acetone, 2,5-hexanedione, diethyl ether, 1,2-dimethoxyethane, benzyl alcohol and cyclohexanol at concentrations of 0.1 to 1.0 mol.kg(-1) were determined at temperatures of 298.15, 423.15, 473.15 and 523.15 K and pressures up to 28 MPa. The measurements were performed at ambient conditions using the commercial Picker differential flow calorimeter and at high temperatures and pressures with a customized Picker type calorimeter constructed at the Blaise Pascal University, Clermont-Ferrand. Standard molar heat capacities were obtained by weighted extrapolation to the infinite dilution limit. The contributions of -CO-, -O- and -OH groups to the standard molar volume and standard molar heat capacity were determined from the newly determined and literature data. The variation of the three oxygen-containing group contributions with temperature and molecular structure is examined qualitatively.