CALCULATION OF THE STANDARD PARTIAL MOLAL THERMODYNAMIC PROPERTIES AND DISSOCIATION CONSTANTS OF AQUEOUS HCL0 AND HBR0 AT TEMPERATURES TO 1000°C AND PRESSURES TO 5 KBAR

Abstract

Dissociation constants of aqueous ion pairs HCl0 and HBr0 derived in the literature from vapor pressure and supercritical conductance measurements and were used to calculate the standard partial molal thermodynamic properties of the species at 25°C and 1 bar. Regression of the data with the aid of revised Helgeson-Kirkham-Flowers equations of state , and resulted in a set of equations-of-state parameters that permits accurate calculation of the thermodynamic properties of the species at high temperatures and pressures. These properties and parameters reproduce generally within 0.1 log unit (with observed maximum deviation of 0.23 log unit) the log K values for HBr0 and HCl0 given by Quist and Marshall (1968b) and Frantz and Marshall (1984), respectively, at temperatures to 800°C and pressures to 5 kbar.