Enter the forward activation energy (J) and the change in enthalpy (J/mol) into the calculator to determine the Reverse Activation Energy.

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## Reverse Activation Energy Formula

The following equation is used to calculate the Reverse Activation Energy.

RAE = FAE - dH

Variables:

- Where RAE is the Reverse Activity Energy (J)
- FAE is the forward activation energy (J)
- dH is the change in enthalpy (J/mol)

To calculate the reverse activity energy, subtract the change in enthalpy by the forward activation energy.

## How to Calculate Reverse Activity Energy?

The following two example problems outline the steps and information needed in order to calculate the Reverse Activity Energy.

**Example Problem #1:**

- First, determine the forward activation energy (J). In this example, the forward activation energy (J) is measured to be 41.
- Next, determine the change in enthalpy (J/mol). For this problem, the change in enthalpy (J/mol) is calculated to be 3.
- Finally, calculate the Reverse Activation Energy using the formula above:

RAE = FAE – dH

Inserting the values from above and solving the equation with the imputed values gives:

RAE = 41 – 3= 38(J)

**Example Problem #2: **

Using the same process as example problem 1, we first define the needed variables outlined by the formula. In this case, the values are provide as:

forward activation energy (J) = 400

change in enthalpy (J/mol) = 24

Entering these values into the formula or calculator above gives us: RAE = 400 – 24 = 376 (J)