Redox Reactions-
This is an option for advanced users who are familiar with these types of reactions.
If there is evidence that two species coupled by a redox reaction occur simultaneously in significant concentrations in a solution, then both species should be included in the calculations as input metals and ligands and no redox reactions should be considered. If there is reason to believe that a redox half reaction is occurring in a system, then the reaction may be included in the calculations.
Open the "Advanced Options" area of the program to input values used to calculate redox reactions.
Redox Reactions- check off the box and enter the appropriate reaction codes.
Electron Activity- Enter the electron activity derived from pE (-log electron activity) as a means of expressing redox level. Unlike Geochem-PC the electron activity is not entered as pE, but as [e-].
If you are unfamiliar with calculating electron activity, then please consult the appropriate texts on redox chemistry.
N2 Partial Pressure: Enter the partial N2 pressure; used only for redox calculations involving NO3-. The value will almost always be 10^(-0.1) atmospheres.
To learn more about how to set up these type of Geochem files please load: "Example 6 Redox Rxns B & CC.geo"and "Example 7 Type A Redox rxn.geo".
The text and table below were extracted from the Geochem-PC 2.0 User Notes. Thanks to Dave Parker and Bud Norvell.
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