Abstract
Accurate values of the apparent standard partial molal Gibbs free
energies of formation (Delta (G) over bar degrees) of aqueous species,
minerals, and gases at high temperatures and pressures are a requisite
for characterizing a variety of industrial and natural processes
including corrosion of metals, solvent extraction, crystal growth,
metamorphism, and the formation of hydrothermal ore deposits. Revision
of the HKF equations of state for aqueous species other than H2O
(Helgeson, Kirkham and Flowers, 1981) by Tanger and Helgeson (1988)
and Shock et al. (1992) permits calculation of Delta (G) over bar
degrees for these species at temperatures to 1000 degrees C and pressures
to 5000 bars. The revised equations of state were combined with parameters
generated by Shock and Helgeson (1988, 1990), Shock et al. (1989),
Sassani and Shock (1990), Shock and McKinnon (1993), Shock and Koretsky
(1993), Schulte and Shock (1993), Pokrovskii and Helgeson (1995 a,
b, and c), and Sverjensky et al. (1995) together with densities and
electrostatic properties of H2O computed from equations summarized
by Johnson and Norton (1991) to calculate values of Delta G degrees
for aqueous species as a function of temperature and pressure. The
results of these calculations are tabulated for 348 such species,including
both inorganic and organic aqueous ions, neutral species, and metal
ligand complexes. Similar calculations using equations, parameters,
and thermodynamic data taken from Kelley (1960), Helgeson er al.
(1978), Wagman et al. (1982), Hill (1990), Shock (1993), and Pokrovskii
and Helgeson (1995 a and b) were used to generate tables of Delta
(G) over bar degrees for H2O, 22 minerals, and 18 gases. The tabulated
values of Delta (G) over bar degrees which were generated with the
aid of SUPCRT92 (Johnson et al., 1999), facilitate considerably assessment
of the thermodynamic behavior of chemical processes at both high
and low temperatures and pressures. (C) 1995 American Institute of
Physics and American Chemical Society.
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