A reaction produces 72 cm3 of gas in 90 s. Calculate the mean rate of gas production.
[2 marks]
Total for this question: 2
All calculations
Mean rate of reaction
Rates of reaction
AQA 8462
ORIGINAL
mean rate = amount of reactant used or product formed / time
Rate is a change divided by the time interval, with both quantities carrying units.
Board and spec code confirmed against AQA 8462 · registry checked 2026-07-17How this checking works
Work it, then mark it
Do each calculation on paper first, then reveal the mark scheme and tick the marks you actually earned — the same way you should mark past papers.
Q1
Do the calculation on paper first — then mark it.
Where the marks get lost
- Multiplying amount by time.
- Giving a number without compound rate units.
Exam tip: Read the time interval carefully: final time minus initial time, not always the final time alone.
Calculations are the most trainable marks in chemistry
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Stuck on mean rate?
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