- The representation of rate of reaction in terms of molar concentration of the reactants participating in a reaction raised to some power is called rate law.
- It is also called rate expression or rate equation.
- Consider a reaction:
2NO (g) + O2 (g) --> 2NO2
Rate ∝ [NO]2
Rate ∝ [O2]
Combining these two rates we derive
Rate ∝ [NO]2 [O2]
Rate =k [NO]2 [O2]
- Where k is the proportionality constant with a definite value at a specific temperature for a specific reaction and is called Rate Constant.
- Rate law expression = -d[R]/ dt = k [NO]2 [O2]