Theories Of Reaction Rates

The units of the rate constant depend on the order of the reaction. For a reaction with rate constant k and the following rate laws:
- For zero order: k has units of mol/L/s.
- For first order: k has units of 1/s.
- For second order: k has units of L/mol/s.
Since the given rate constant is 4.5 × 10−5 L mol−1 s−1, it matches the units for a second-order reaction.