Activation Energy Calculator

Utilise online Activation Energy Calculator to find the minimum amount of energy needed to happen a chemical reaction. This calculator uses the Arrhenius equation to get the activation energy of a reaction. Just enter the temperature, rate coefficient, pre-exponential factor in the given inputs and click the calculate button. At the output section, you can see the exact activation energy value along with the detailed steps.

Rate Coefficient(k)
Activation Energy(Ea)

Energy of Activation Calculator: Need to calculate the activation energy of a chemical reaction in a fraction of seconds? Then, you can use this online Activation Energy Equation Calculator tool. Energy Activation Calculator gives the accurate answer along with the step by step explanation. Moreover, you will learn about the activation energy equation, definition and how to solve the AE questions on this page.

Steps to Calculate Activation Energy

Go through the detailed step by step process to compute the minimum energy required for a reaction to happen. Follow these guiding Principles and instructions to get the result easily.

  • Find the temperature, rate coefficient and constant.
  • Multiply the universal gas constant with the temperature
  • Divide the reaction rate coefficient by the pre-exponential factor.
  • Get the logarithm of the above division.
  • Multiply it with the negative of the obtained product to know the activation energy.

Activation Energy Definition

Activation energy is defined as the minimum energy recommended for a chemical reaction to occur. This energy is required for many types of reactions, for example, combustion. Each time you want a light, you need to provide energy. That's why your matches don't combust spontaneously.

The SI unit of activation energy is Joules (J). The other units are kilojoules per mole (kJ/mol) or kilocalories per mole (kcal/mol).

Activation Energy Formula

The activation energy of every reaction can be calculated with the help of the Arrhenius equation.

Eₐ = -R * T * ln(k/A)


Eₐ is the activation energy of the reaction

R is the universal gas constant = 8.314 J/(K*mol)

T is the temperature in kelvins

A is the pre-exponential factor. This coefficient does not depend on the temperature and is constant for a reaction

k is the reaction rate coefficient and it depends on temperature


Question: Find the activation energy of the chemical reaction, if the rate coefficient is 3 1/sec, the factor is 10 M-1s-1, the temperature is 150 K.


Given that

Reaction rate coefficient k = 3 sec-1

Pre-exponential factor A = 10 s-1

Temperature T = 150 K

Activation energy Eₐ = -R * T * ln(k/A)

= -8.134 * 150 * ln(3/10)

= -8.314 * 150 * (-0.522)

= 1501.47 Joules

Therefore, the activation energy is 1501.47 J.

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activation energy Calculator

FAQ’s on Arrhenious Calculator Activation Energy

1. What is the activation energy equation?

The activation energy for any reactant can be find using the Arrhenius equation. The formula is Ea = -R * T * ln(k/A). Here R is the gas constant, T is the temperature, k is the reaction rate coefficient, Ea is the activation energy of the reaction, and A is the pre-exponential factor.

2. How to find activation energy?

The activation energy of a reaction can be calculated using these steps. Divide the reaction rate coefficient by the exponential factor and find the log of the value. Multiply it with the gas constant, temperature. The negative of the product is the energy of activation.

3. What is the activation energy?

The activation energy is defined as the minimum amount of extra energy required by reacting molecules to get converted into product. It can also be described as the minimum energy required to activate or energize atoms or molecules that undergo chemical reaction or transformation.

4. What are the factors affecting activation energy?

The activation energy depends on two factors. They are the nature of reactants, the effect of catalysts. In the case of covalent reactants, the activation energy is high because energy is needed to break the older bonds. In ionic reactants, the value of Ea is low because there is an attraction between reacting species.