AP Chemistry / Unit 5: Kinetics
5.4 Elementary Reactions
Notes
An elementary reaction happens in one step; its rate law comes straight from its coefficients.
- Molecularity: unimolecular, bimolecular, termolecular (rare).
Practice
For the elementary step $2NO_2\to NO_3+NO$, the rate law:
Use the coefficients.
A step with two reactant particles colliding is:
Two molecules.
Coefficients can be used as orders only for:
Overall reactions need experiments.
Ready for more? Take the Unit 5 test.