Measurements of the heats of dilution and description of the system H2O/H2SO4/HCl with a solvation model

Heat of dilution measurements have been performed on the system H2O/H2SO4/H Cl in the concentration range of 0.3 mol% to 20 mol% electrolyte and in the temperature range of 20 degrees C to 60 degrees C. The constituent binary systems H2O/H2SO4 and H2O/HCl could be described using the solvation model introduced by Engels [H. Engels, Anwendung des modells der lokalen zusammen setzung auf elektroytlosungen, Dissertation, RWTH Aachen, 1985]. The vapor- liquid-equilibria (VLE) and the thermal properties are described simultaneo usly by one set of parameters. Applying the solvation model to the ternary system H2O/H2SO4/HCl, the measured heats of dilution as well as VLE-data ta ken from the literature could be predicted. The heat of dilution data are p resented with a mean relative deviation of 3.5%. The boiling temperatures o f the three sources of ternary VLE data considered in this paper are predic ted with a mean absolute deviation of less than 1.2 K. The corresponding me an absolute deviations of the vapor mole fractions of HCl are within 0.06. (C) 1998 Elsevier Science B.V. All rights reserved.