Is there a database that can calculate activity coefficients with the Debye-Huckel model and the Davies equation while maintaining the same model for the activity of water?
I am trying to determine how Fe concentrations, buffered by the reaction:
Pyrite + 4Fe2+ + 4H2O = 8H+ + Magnetite + Pyrrhotite
change as a function of activity coefficient model.
So far I have used thermo.dat for the Debye-Huckel model, and PHREEQC for the Davies equation ( I set ion size = 0 for all charged species). I fix pH at a constant value. The differences in calculated activity of Fe2+ are small, but it would be great if there were no difference at all.
Thank you