\(E_a = -R \times T \times ln(\dfrac{k}{A})\)

Temperature (T)
Reaction rate coefficient (k)
Frequency factor (A)

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Our Activation energy calculator plays a Major role in determining the feasibility and rate of chemical reactions. Understanding this concept is fundamental for scientists and engineers alike. This article explains what activation energy is, why it is important, and how to calculate it using an Activation Energy Calculator.

What is Activation Energy?

Activation energy is the minimum amount of energy required for a chemical reaction to occur. It represents the energy barrier that molecules must overcome to initiate a reaction. In simpler terms, it's the energy needed to break the bonds of reactant molecules and start the formation of products. For those needing assistance with complex calculations, such as determining ratios in reaction rates, using a fraction calculator online can be quite helpful.

The Formula for Activation Energy:

The Arrhenius equation is commonly used to calculate activation energy (πΈπ‘Ž). It relates the rate constant (π‘˜) of a chemical reaction to the temperature (𝑇) and activation energy (πΈπ‘Ž):

\(k = A e^-{\dfrac{E_a}{RT}}\)


  • k = Rate constant of the reaction
  • A = Pre-exponential factor (frequency factor)
  • πΈπ‘Ž= Activation energy
  • R = Gas constant (8.314 J/mol·K)
  • T = Absolute temperature in Kelvin

Units of Activation Energy

The units of activation energy are typically expressed in joules per mole (J/mol) or kilojoules per mole (kJ/mol). This unit measures the amount of energy required per mole of reactant molecules to overcome the energy barrier and initiate a reaction.

Activation Energy Formula Table:

Certainly! Here's a structured table outlining the components and parameters typically included in a Botox Cost Calculator:

Symbol Description Units
π‘˜ Rate constant mol/L·s (or as per reaction order)
𝐴 Pre-exponential factor (Frequency factor) Same as rate constant
πΈπ‘Ž Activation energy J/mol
𝑅 Gas constant 8.314 J/mol·K
𝑇 Temperature Kelvin (K)

The Importance of an Activation Energy Calculator:

An activation energy calculator is a valuable tool in the fields of chemistry, biology, and engineering for various reasons. It provides a convenient and efficient way to determine the activation energy (E_a) of chemical reactions, which is essential for understanding reaction kinetics, optimising processes, and enhancing product development.

Example of Activation Energy

How to find activation energy with temperature and rate constant as follows:

Temperature = 253 K

Frequency factor = A = 210

Rate Constant = 100


E_a = -R * T * ln(k / A)

E_a = -0.008314 * 373.15 * ln(100 / 1000)

E_a = (-3.1023691) * (ln(0.1))

E_a = (-3.1023691) * (-2.302585092994)

E_a = 7.143 KJ

Our calculator also computes the same answer but reduces the times from minutes to milliseconds. The tool maintains accuracy in calculations and shows complete steps that are involved in calculating activation energy.

How to calculate the Activation Energy

To calculate the activation energy:

  • Begin with measuring the temperature of the surroundings. We can assume you're at room temperature (25 °C).
  • Then, choose your reaction and write down the frequency factor. For example, for reaction 2ClNO → 2Cl + 2NO, the frequency factor is equal to A = 9.4×109 1/sec.
  • Choose the reaction rate coefficient for the given reaction and temperature. Let's assume it is equal to 2.8373×10-8 1/sec.
  • Input all these values into our activation energy calculator. It will find the activation energy, which, in this case, is equal to -100 kJ/mol.


How does an activation energy calculator work?

An activation energy calculator utilises experimental data and mathematical equations to compute the activation energy of a reaction.

How is activation energy related to temperature?

Activation energy is inversely related to temperature. As the temperature increases, more reactant molecules have sufficient energy to overcome the activation energy barrier, leading to an increased reaction rate.

Can activation energy be negative?

No, activation energy cannot be negative. A negative value would imply that reactants gain energy as they transform into products, which contradicts the fundamental principles of energy conservation in chemical reactions.

How is activation energy calculated?

Activation energy is often calculated using the Arrhenius equation, which relates reaction rate constants to temperature. For those needing to determine electrical properties, a capacitor calculator online can be a useful tool.