THERMODYNAMIC ACTIVITIES AND EQUILIBRIUM PARTIAL PRESSURES FOR AQUEOUS SULFURIC-ACID-SOLUTIONS

Published room-temperature and azeotroplc composition data for solutions together with recently published high-temperature P-T-X data and room-temperature values (or the equilibrium vapor pressure of sulfur-bearing species over concentrated sulfuric acid-water solutions are evaluated critically for self-consistency. The adjusted data are used to calculate activity coefficients at 0°C and at the normal azeotroplc boiling temperature and to generate expressions for the partial molar heat capacities in H2SO4-H2O solutions. These partial molar properties, calculated for temperatures between 25 and 320°C and spanning the composition range from pure water to the azeotroplc composition, are used as interpolation formulas for the calculation of basic thermodynamic parameters of H2SO4-H2O solutions that are specifically needed for nucleation and precipitation phenomena involving vapors with a high sulfur oxide and/or sulfuric acid content. © 1990, American Chemical Society. All rights reserved.