LuduminaPM-06 · PM-U3 · Planned
Gas pressure and volume
Learning objectives
Use fixed-mass constant-temperature gas data to calculate pressure/volume changes; explain the inverse relation.
8463 §§4.3.3.2 / No Trilogy counterpart
DfE single-science pp.42–43 / Combined pp.35. Evidence checked 30 September–1 October 2026. Skills: WS1.2,2.2; MS3b,3c,4a.
Needs firstPM-05
Explanation
The pV relation requires a fixed amount of gas at constant temperature. Reducing volume raises collision frequency at the walls and increases pressure. If the gas also warms, the same fixed pV model does not apply.
Concepts, equations and units: pV=constant, p1V1=p2V2; Pa,m³; mass and temperature held fixed.
Prediction, demonstration and game exercise
Predict, observe, explain
Compress a model slowly while heat exchange holds temperature fixed; compare collision frequency.
Planned learner game exercise
Set syringe volume for a target pressure and select only constant-temperature datasets.
Independent practice
Three p/V problems and a p–V graph; optional p–1/V straight line.
Original practice example · Separate Physics
A gas at 100 kPa occupies 0.002 m³. It compresses to 0.001 m³ at constant temperature. Find pressure.
Show working and model answer
Working / reasoning
p2 = p1V1/V2 = 100 × 0.002/0.001 kPa.
Answer
200 kPa.
Exit check and success criteria
Two values correct and both validity conditions stated.
During practice, compare the prediction with evidence and give an error-specific prompt. The exit item uses a fresh context or fresh values, answered independently.
Misconceptions, practical links and mastery
Check these misconceptions
pV remains constant while temperature changes; volume halves so pressure halves.
Practical preparation
Optional teacher-supervised syringe/data investigation; not an RP.
Virtual preparation and revision only. Required hands-on activities and school records remain separate.
Proposed mastery
0: not yet evidenced. 1: supported. 2: independent exit criteria met. 3: successful changed-context transfer. Advance at 2; revisit with fresh retrieval. These are not GCSE grades.