Thermodynamic constants

Calculate the thermodynamic constants in sea water. The calculated constants are on the SWS pH scale. The thermodynamic constants are calculated in mmol/kg (mmol/l). This script uses the formulas from MILERO (GCA, 1995) and CLEGG AND WHITFIELD (GCA, 1995), with corrections for the pressure from MILERO (1983, CHEM. OCEAN v. 8), and UNESCO (1983). The original FORTRAN code has been written by B.P. BOUDREAU (COMPUTERS & GEOSCIENCES, 1996) for the numerical diagenetic model CANDI.

Enter values for T, S, P to calculate thermodynamic constants of sea water under those conditions:

Parameter Unit Range User-input
Temperature C 0-40
Salinity PSU (ppt) 0.5-43
Pressure atm (1 atm at surface) 0-1200

dissociation constant of H2O
1st dissociation constant of CO2(aq)
2nd dissociation constant of CO2(aq)
dissociation constant of B(OH)3
1st dissociation constant of H3PO4
2nd dissociation constant of H3PO4
3rd dissociation constant of H3PO4
dissociation constant of HNO3
dissociation constant of NH4
1st dissociation constant of H2S
solubility product of CaCO3 (Aragonite)
solubility product of CaCO3 (Calcite)

© Copyright R. Luff (DG2HL) 1997-2000.

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