Scale-up Suite Help
Reaction Lab > Reactions
 What is the 'Reactions in' section?

The model will have a Reactions in section for each phase where reactions occur. By default, there is a Reactions in Solution section. For a biphasic system, you might have a Reactions in Organic and a Reactions in Aqueous section. The phases are named and defined in the Process Scheme section, and the names of the Reactions in sections come from the phase names, which can be edited by the user.

You will see below that it is easy to add reaction lines in this section.  Please adopt the following best practices in order to develop successful and chemically realistic models:

 Example for the Heck Reaction model

Below is the catalytic cycle for the Heck reaction where each step is labeled with a reaction number:

This can be written into Reactions in Solution as follows. Note that the Na cation and NaBr has been omitted for clarity:


 How to type in a second order reaction

Using the Heck Reaction model as an example, the input of a second order reaction is shown below:



You will see that once the reaction is entered and the Enter button is pressed, the reactants 4-bromobenzaldehyde and Pd_cat will be in the Reactants column and the product for the elementary reaction, Int_1, will be in the products column. When the reaction is created, you will see a slider bar in the forward rate column. This is used to increase/decrease the reaction rate. If you want to input your own value, click on the  icon on the right-hand side and this will show the kinetics parameters.

 How to type in a reaction that is in equilibrium

There are two ways to do this:

1. You can type in a reaction separating the reactants and products with an equals (=) sign.

2. You can type in a forward reaction, and click in the reaction arrow to make it reversible. Clicking on the arrow again will make the reaction irreversible again.

Both cases are shown below using the Heck reaction model:

 Use of pKa and pKb

If you would prefer to type in the pKa value rather than the equilibrium constant as it is more accessible (for example, the pKa of Acetic acid is 4.75). There is a dropdown menu located to the left of the equilibrium constant value. Clicking on this will bring you to a dropdown menu that contains pKa and pKb. Select pKa from this menu. Then type in the pKa value instead of the equilibrium constant.


 How to check whether a reaction is balanced

If you want to find out if a reaction is mass balanced, go to the Bal column. If it is checked, then it is balanced. Similarly, if you want to check if the reaction is charge balance go to the [+/-] column if this is checked, it is charge balanced.

If either of these are not balanced you will see one of the following icons , the former means that the products side is lighter, and the latter is that the reactants side is lighter.