To open the Reactions interface do one of the following:
.Only the values in bold cells are editable. These editable values relate to the parameters you have set up on the Process sheet.
Right-click in the Set Reactions window in a non-editable cell and select a View from the dropdown menu:
You can also double-click in the title bar of the window to toggle between these views. You can use right-click in the title bar or use Ctrl+X to close the window.
It is recommended when manually pre-fitting rate constants in DynoChem, to fit to experimental data taken at the reference temperature, but then to fit activation energies to experiments conducted at other temperatures.
If you switch on the ghostlines function in the main chart you can compare the results of changing kinetics between the current and the previous run.
You can update the model in memory to keep your currently fitted values and re-use then in the fitting module.
If you have set the value of a kinetic parameter in a Calculate statement it will be unavailable for editing in Set Reactions.
If you have set the value of a kinetic parameter on the Scenarios sheet, it is available for editing in Set Parameters (with the other Scenario items), but unavailable in Reactions.
The forward (k>) rate constants and equilibrium constants (Keq) are the values you set in the Process sheet at the reference temperature (Tref).
It is recommended when manually pre-fitting rate constants in DynoChem, to fit to experimental data taken at the reference temperature, but then to fit activation energies to experiments conducted at other temperatures.
Setting activation energies to zero will make the rate constants independent to variations in process temperature.
You can only edit Arrhenius pre-exponential factors in Reactions if you have set them in the Process sheet of the model. The values of k> and k< are displayed for information at a default reference temperature of 20 C, i.e. k> = k0>.exp (-Ea> / RTref) where Tref = 20 C = 293.14 K.
The displayed values of k0 in the 'Full' view are calculated from the rate constants, Tref and the activation energies, i.e. k0> = k>.exp(Ea>/RTref). In this case the k0 values are displayed for information only and are not editable. Note: when an activation energy is set to zero the displayed k0> value is equal to the rate constant k>.
As per convention, negative values of reaction heat indicate that the forward reaction is exothermic.
Reaction orders can only be set in the Full view of Set Reactions. The first reaction order displayed in the Reactions table refers to the first species defined in the reaction equation, i.e. nitro in the reaction: Nitro+ H2 -> Nitroso.
To ensure consistency in the model, editing reaction orders updates the rate expression and the units of the rate constant. For example, in a reaction A -> P, if you change the reaction order on a species A from 1 to 2 this will automatically change the rate expression from k[A] to k[A]^2, and the rate constant units from 1/s to L/mol.s.
Do one of the following: