8.2.2—Sketch and use the Boltzmann distribution
- Syllabus
- 9701–2028–2029
- Objective
- 8.2.2
- Level
- AS
A Boltzmann distribution shows the spread of particle energies
A Boltzmann distribution plots the number or fraction of particles against their kinetic energy at a particular temperature. The area represents the total population.
The curve is broad rather than a single value. The fraction with energy above Eₐ is the area to the right of the Eₐ line, representing potentially successful collisions.
Raising temperature broadens and flattens the curve, shifts the most probable energy higher and increases the area beyond Eₐ, so rate rises.
The peak height is not the reaction rate. Compare the area beyond Eₐ and remember the total area remains tied to the particle population.
ConceptA-Level CAIE Chemistry AS