Catalyst & Activation Energy
See how a catalyst lowers the activation energy barrier and speeds a reaction.
About the Catalyst & Activation Energy
Free catalyst simulation. Adjust activation energy, reaction enthalpy and add a catalyst to see the energy profile diagram change and the reaction speed up. Built for reactions & kinetics, the catalyst & activation energy runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
See how a catalyst lowers the activation energy barrier and speeds a reaction. Use it to explore reactions & kinetics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Catalyst & Activation Energy
- Use the controls to change Activation energy Ea, Reaction energy ΔH, Catalyst strength, Temperature. The simulation reacts instantly.
- Press "Run reaction" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Add a catalyst and read the speed-up.
- Raise the temperature.
- Make an endothermic reaction.
- Click Run reaction.
Key ideas you can learn
- A catalyst provides a different route with a lower activation energy.
- It speeds up both forward and reverse reactions equally and is not used up.
- It does not change the overall energy change (ΔH) of the reaction.
Where this is used in the real world
Catalysts are in car exhausts, fertiliser factories, oil refineries and your own enzymes. They save huge amounts of energy.
Who is this simulation for?
Students learning reaction rates, equilibrium and equations, and teachers who want a visual way to explain what happens to particles.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Does a catalyst change the products or the yield at equilibrium?
No. It only makes the reaction reach equilibrium faster. The equilibrium position stays the same.
What is activation energy?
The minimum energy needed for a collision to start a reaction: the height of the energy barrier between reactants and products.
Is the Catalyst & Activation Energy free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Catalyst & Activation Energy work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.