Molar enthalpy increments for (0.5H(2)O+0.5C(2)H(5)OH) at temperatures up to 573.2 K and pressures up to 11.3 MPa

Measurements of molar enthalpy increments for (0.5H(2)O + 0.5C(2)H(5)OH) ar e reported. A counter-current water-cooled Row calorimeter was used to meas ure 76 enthalpy increments over the temperature range 373.2 K to 573.2 K at pressures from 0.1 MPa up to 11.3 MPa. Extrapolation of the gas phase meas urements to zero pressure gave values in excellent agreement with the mean of the pure component ideal gas enthalpies calculated from spectroscopic da ta. Liquid phase enthalpy increments at temperatures in the range 423.2 K t o 523.2 K and at the pressures (5.0, 10.0, and 15.0) MPa were calculated fr om excess enthalpy measurements combined with pure component enthalpy incre ments. At the pressures (5.0 and 10.0) MPa these enthalpy increments were f ound to be in excellent agreement with the new measurements. The boundary o f the two phase region was constructed with the aid of data derived from (v apour + liquid) equilibrium measurements. Enthalpies of flash vaporization of the mixture at x = 0.5, obtained from the boundaries of two phase region , lie between the enthalpies of vaporization of the purr: components. (C) 2 000 Academic Press.