Ideal gases — AS & A Level Physics (9702) questions by topic
Ideal gases questions define an ideal gas and the Avogadro constant, rearrange a pV = nRT relationship to make temperature the subject, and sketch pressure-volume changes correctly, weighted from 8 to 13 marks.
State, calculate and deduce top the command words in this A Level Physics topic, with draw and explain also common: draw a curve rather than a straight line between two states, and state the exact value of absolute zero. 14 real questions from 2023 to 2025 papers sit here. Submitting each attempt for instant marking catches an un-rearranged starting equation or a contradicted relationship immediately, rather than after the whole gas-laws section is attempted.
What examiners look for
- Examiners note candidates sometimes refer to the volume of the gas rather than the volume of the particles, or to the volume of a single particle incorrectly.
- A common mistake is not rearranging the starting equation to make temperature the subject before substituting values.
- A recurring criticism is drawing a line as straight rather than as a curve between two labelled states on a pressure-volume graph.
- Reports flag candidates giving a correct relationship but then contradicting it by claiming it only applies under certain conditions.
- Strong answers define every symbol used, including specifying 'thermodynamic temperature' for T, and correctly complete a full data table.
May–June 2025, Paper 41
State what is meant by the internal energy of a system.
Answer this question and get it marked →May–June 2025, Paper 42
The equation of state for an ideal gas may be written as pVA = NBT, where p is the pressure of the gas, V is the volume, A is the Avogadro constant, B is another constant, and N…
Answer this question and get it marked →May–June 2025, Paper 44
May–June 2024, Paper 41
May–June 2024, Paper 43
October–November 2024, Paper 41
State what is meant by the Avogadro constant.
Answer this question and get it marked →October–November 2024, Paper 42
State three of the basic assumptions of the kinetic theory of gases.
Answer this question and get it marked →October–November 2024, Paper 43
State what is meant by the Avogadro constant.
Answer this question and get it marked →February–March 2023, Paper 42
May–June 2023, Paper 41
State two of the basic assumptions of the kinetic theory of gases.
Answer this question and get it marked →May–June 2023, Paper 42
May–June 2023, Paper 43
State two of the basic assumptions of the kinetic theory of gases.
Answer this question and get it marked →October–November 2023, Paper 41
The product pV for an ideal gas is given by pV = (1/3) Nm <c^2 where p is the pressure of the gas and V is the volume of the gas. State the meaning of the symbols N, m and <c^2 in…
Answer this question and get it marked →October–November 2023, Paper 43
The product pV for an ideal gas is given by pV = (1/3) Nm <c^2 where p is the pressure of the gas and V is the volume of the gas. State the meaning of the symbols N, m and <c^2 in…
Answer this question and get it marked →Other AS & A Level Physics topics
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