Chemistry A-Level
orders and molecularity
What orders and molecularity means in Chemistry A-Level, as defined for AQA.
Definition of orders and molecularity
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Reference: AQA
A species to the first power contributes one molecule to the rate determining step, one to the second power contributes two, and a zero order species is involved only in a fast step after it.
Topics that use orders and molecularity
- Determination of rate equation (A-level only) (AQA A-Level)
Related terms
- Constant half-life
- continuous monitoring
- deriving the rate equation
- evidence for mechanism
- iodine clock
- multi step mechanisms
- rate against concentration graphs
- Rate-determining step
Using orders and molecularity in the exam
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