AQA and OCR A · Year 13 physical chemistry
Rate equation question generator
Generate fresh initial-rates tables, determine individual reaction orders, write the rate equation, and calculate the rate constant with the correct units.
Initial-rates questions
Build the rate equation from experimental data
I’d start by finding the cleanest pair of experiments: ideally one concentration changes while the others stay fixed. In harder tables, use an order you already know to account for one change before solving the next one.
Finding orders from initial rates
Use ratios between experiments to determine each power in the rate equation. For zero order, changing that concentration leaves the rate unchanged; first order gives the same factor change in rate; second order gives the square of the concentration factor.
For challenge and master questions, pin down one order first. Account for its effect on the rate, then use the remaining change to find the next order.
AQA and OCR A coverage
AQA and OCR A both cover initial rates, rate equations, overall order, rate constants and units. Half-life evidence appears only in the OCR A mode of the Order Detective.
Rate Equation Order Detective
Deduce orders from concentration changes, graph descriptions, units of k and OCR-only half-life clues.
Open the detective game → Related calculationArrhenius equation practice
Calculate activation energy or a rate constant using logarithmic forms of the Arrhenius equation.
Practise Arrhenius → Visual modelBoltzmann distribution
See how temperature and catalysts change the fraction of particles able to react.
Open the simulator →