Reaction orders · evidence · board-aware practice
Rate Equation Order Detective
Solve generated case files using concentration effects, graph descriptions, the units of k and combined changes. OCR A mode can also include first-order half-life evidence.
Evidence case file
Infer the hidden rate law
Each case contains enough information to find every order. Harder cases require you to combine two or more clues.
Reading the evidence
A case may describe how the initial rate responds to a concentration change, the shape of an initial-rate graph, or the units of the rate constant. Hard cases can give a combined concentration change: once one order is known, its contribution can be divided out to reveal another.
OCR A half-life evidence
In OCR A mode, a constant half-life is evidence of first-order behaviour. AQA mode does not use half-life clues.
Use both rates games
This detective game develops interpretation. The initial-rates generator develops full numerical working, calculation of k and units, and multi-experiment comparisons.