Explore the Enthalpy & Activation Energy Diagram
Drag the reactant, peak and product levels of an energy profile and see ΔH, Ea and the effect of a catalyst. Free, no signup, runs in your browser.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
Illustration. Open the tool for the real thing.
See it in action
The Enthalpy & Activation Energy Diagram with sample data entered and the result showing.
What is the Enthalpy & Activation Energy Diagram?
Drag the reactant, peak and product levels of an energy profile and see ΔH, Ea and the effect of a catalyst. It runs in your browser, so a change to a setting or a drag on an object shows up at once.
Industrial catalysts, hand warmers, cold packs, rocket fuels and the design of every chemical plant depend on energy profiles.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
ΔH is the energy of the products minus the energy of the reactants.
Negative ΔH is exothermic; positive ΔH is endothermic.
Activation energy is the height of the barrier the reaction must climb.
Make ΔH negative, then positive.
Drag the peak up and roll the ball.
Turn the catalyst on and compare Ea.
Used for
Pick one to see how it fits.
Reactions & Kinetics learners
Students learning reaction rates, equilibrium and equations, and teachers who want a visual way to explain what happens to particles.
Try it freeTeachers
For teachers: project the Enthalpy & Activation Energy Diagram on the board, let students predict the result, then run it together and test this: Drag the peak up and roll the ball. For students: change one thing at a time and write down what changes.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This simulation | Textbook diagram | |
|---|---|---|
| Interactive | Drag, tap and change settings | Fixed picture |
| Install | Nothing to install | Not needed |
| Cost | Free to use | Depends on the book |
Questions people ask
What is activation energy?
The minimum energy that colliding particles need to react, shown as the height from reactants to the peak.
Does a catalyst change ΔH?
No. It only lowers the activation energy, so the reaction is faster but releases or absorbs the same heat.
Is the Enthalpy & Activation Energy Diagram free to use?
Yes. The Enthalpy & Activation Energy Diagram is free, needs no signup or download and runs in your web browser. It is part of the Reactions & Kinetics group of AZRS simulations.
Does the Enthalpy & Activation Energy Diagram work on a phone or tablet?
Yes. The Enthalpy & Activation Energy Diagram takes touch input as well as mouse input, so you can use its 3 adjustable settings with a finger. A larger screen makes the controls and graphs easier to read.
How do I use the Enthalpy & Activation Energy Diagram?
1. In the Enthalpy & Activation Energy Diagram, use the controls to change Activation energy Ea, Enthalpy change ΔH, Catalyst. The simulation reacts instantly. 2. In the Enthalpy & Activation Energy Diagram, pick an option such as Off, On to switch modes or load an example. 3. In the Enthalpy & Activation Energy Diagram, press "Roll the ball", "Reset" to start, reset or change what is happening. 4. Start with this experiment: Make ΔH negative, then positive. Drag any glowing handle, object or slider with your mouse or finger and the Enthalpy & Activation Energy Diagram responds in real time. 5. Change one setting at a time and watch which readout moves, then compare it with this idea: ΔH is the energy of the products minus the energy of the reactants.
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Try the Enthalpy & Activation Energy Diagram now
Drag the reactant, peak and product levels of an energy profile and see ΔH, Ea and the. Free to use.
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