Input Editor Pane Chemical Reactions

In this pane all parameters for chemical (equilibrium and kinetic) reactions are set.

The name of the reaction serves as descriptive identifier and must be unique.

The type of a reaction can not be changed.

Adding and removing chemical reactions

A new chemical reaction can be added by invoking the "Add new reaction" button. A dialog box will appear that requires the input of the name and the type (equilibrium or kinetic) of the reaction. Pressing Cancel or closing the window will abort the addition of the new reaction.
Note: The newly added reaction is initially invalid. You will have to add at least one reactant and product species to make it a valid reaction.

The selected reaction can be removed by invoking the "Remove selected reaction" button.
Note: No confirmation for the removal of the selected reaction is required. All data of this reaction will be lost once the button is activated.

Modifying the reaction rates and the stoichiometric coefficients of reactants and products of the selected reaction

In the lower half of the input pane the parameters for the selected reaction are displayed.

For equilibrium reactions the log10 of the equilibrium constant has to be set.
For kinetic reactions the log10 of forward and backward rate constants have to be set.

The stoichiometric coefficients for reactants and products are modified in the two tables at the bottom of the pane. The user has to ensure the consistency of the data entered in the pane "Chemical species", where the stoichiometric coefficients are entered in terms of components. In the reaction pane, stoichiometries are given in terms of species.

Adding and removing reactants and products of the selected reaction

Reactants and products can be added and removed by using the four buttons above the two tables. The following rules for the allowed number of reactants and products apply:

• Ion exchange (IE) reactions, whether equilibrium or kinetic, must have one aqueous species and one ion exchanged species both as reactants and as products. The reactant ion exchanged species must be the reference ion exchange species for the site involved, i.e.:

  Aqueous Species + Reference IE Species <-> New Aqueous Species + New IE Species

  Note: This rule is currently not enforced by the GUI. An incorrect input file for HBGC123D will lead to a simulation error with HBGC123D.
• All other kinetic chemical reactions may involve any species as reactants or products.
• Equilibrium chemical reactions involving aqueous complexation, adsorption or precipitation may involve as many reactants as necessary but must be written as the formation of only one equilibrium product species. Each equilibrium product species may participate in exactly one equilibrium reaction.
  Note: Only the "one product per equilibrium species" rule is currently enforced by the GUI. The user has to ensure that each equilibrium product species participates in only one equilibrium reaction.