What is the rate constant (k)?

The rate constant (k) is a proportionality factor in the rate law that links the reaction rate to the concentrations of reactants.

Key points:

1. Depends on temperature: Higher temperatures usually increase k.
2. Affected by catalysts: Catalysts increase k by lowering activation energy.
3. Independent of concentration: Changing reactant concentrations does not change k.
4. Determines reaction speed: A larger k means a faster reaction for the same reactant concentrations.
5. Units vary: Units depend on the order of the reaction.