Chemistry That Does Work
Rates & Equilibrium
14 minStudent plan
What controls how fast a reaction goes, and what happens when it goes both ways at once.
After this lesson you can
- List what speeds a reaction up, and why each works
- Explain what is still happening at equilibrium
- Predict which way a system shifts when you change it
What speeds a reaction up
Reactions happen when particles collide with enough energy and the right orientation. Anything that increases the frequency or the energy of collisions increases the rate.
Temperature is the strongest lever: raising it increases both how often particles collide and how many exceed the activation energy. As a rough rule, a 10 °C rise roughly doubles the rate.
Concentration and pressure increase how crowded the particles are. Surface area matters for solids, which is why powdered materials react so much faster than a lump, and why fine dusts in flour mills and sawmills are an explosion hazard while the bulk material is not.
A catalyst provides an alternative route with a lower activation energy. It is not consumed, and it does not change how much product you can get, only how fast you get there.
In the full lesson
- What speeds a reaction up
- Reversible reactions
- Le Chatelier's principle
This lesson comes with the Student plan. The first module of Chemistry is free.