Calculate the volume, in dm3, occupied by 0.50 mol of an ideal gas at a temperature of 298 K and a pressure of 100 kPa. (R = 8.31 J/K/mol)
[4 marks]
Total for this question: 4
All calculations
The ideal gas equation
Physical chemistry
AQA 7405
ORIGINAL
pV = nRT (p in Pa, V in m3, T in K, R = 8.31 J/K/mol)
pV = nRT only works in SI units — pascals, cubic metres and kelvin — so convert first.
Board and spec code confirmed against AQA 7405 · registry checked 2026-07-11How 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
- Leaving pressure in kPa or volume in cm3/dm3 — everything must be in SI (Pa, m3, K) before substituting.
- Forgetting temperature must be in kelvin (add 273 to a Celsius value).
- Not converting the final volume from m3 back to dm3 (x1000) or cm3 (x1 000 000).
Exam tip: Convert every quantity to SI on your first line: Pa, m3, K. Then the volume comes out in m3 and you multiply by 1000 for dm3 at the very end.
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