Why temperature, concentration, pressure, surface area and catalysts change the rate, explained with collisions and activation energy.
What you will learn
- Explain each factor with collision theory
- Calculate the surface area to volume ratio of a cube
- Describe how a catalyst works using a reaction profile
Collisions that count
Particles can only react when they collide, and only if they collide with enough energy.
The smallest energy needed is the activation energy.
So a reaction speeds up when there are:
- more frequent collisions (more collisions every second), or
- more energetic collisions (a bigger share with at least the activation energy).
The rest of this lesson and its 12 practice questions are locked.
In this lesson
- Collisions that count
- The factors
- Surface area to volume
- Catalysts
- Try it: Temperature in the simulation
12 practice questions, marked as you go; about 25 minutes in all.
Key terms
Activation energy, More frequent collisions, More energetic collisions, Temperature, Concentration, Pressure, Surface area, Lower activation energy
In this unit: Rates of reaction and equilibrium
Measuring and graphing rates, collision theory and the factors that change a rate, the rates required practical, reversible reactions and how conditions move an equilibrium.
- Measuring the rate of a reaction
- Rate graphs and tangents
- Collision theory and the factors that change a rate
- Required practical: concentration and rate
- Reversible reactions and dynamic equilibrium
- Changing the conditions at equilibrium
- Rates from tangents