Pearson Edexcel International GCSE in Physics · 4PH1 · Free · no account needed
The Gas Laws — exam questions
10 original Incandio exam-style questions on the Gas Laws, 25 marks, about 25 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for The Gas Laws — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
6 command words run through this set, and on Pearson Edexcel International GCSE Physics each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- State (1 mark)
- one precise fact or definition
- Calculate (1–5 marks)
- select the equation, substitute, evaluate — and state the unit Misread as: giving a bare number with no equation and no unit
- Explain (2–4 marks)
- the physics that causes it, set out as a line of reasoning Misread as: describing the change without giving the physical reason for it
- Determine (1–4 marks)
- a value obtained by combining a reading or gradient with a relationship
- Suggest (1–3 marks)
- a plausible answer applying taught physics to an unfamiliar arrangement
Assessed on Paper 1 (4PH1/1P) and Paper 2 (4PH1/2P), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Physics (4PH1) — statements 5.21 · 5.22. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 10 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
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A weather balloon is released from the ground and rises into the upper atmosphere, where both the pressure and the temperature are much lower. The balloon's skin stretches freely, so the gas inside is always at the same pressure as the air around it.
Table 1 — conditions at release and at maximum altitude Pressure / kPa Temperature / °C Volume / m³ At the ground 100 27 8.0 At maximum altitude 10 −53 to be found (a)
(2)Calculate
Calculate the two temperatures in Table 1 in kelvin.
A weather balloon is released from the ground and rises into the upper atmosphere, where both the pressure and the temperature are much lower. The balloon's skin stretches freely, so the gas inside is always at the same pressure as the air around it.
Table 1 — conditions at release and at maximum altitude Pressure / kPa Temperature / °C Volume / m³ At the ground 100 27 8.0 At maximum altitude 10 −53 to be found (b)
(2)Explain
Explain why neither p₁V₁ = p₂V₂ nor p₁ ÷ T₁ = p₂ ÷ T₂ can be used on its own for the balloon.
A weather balloon is released from the ground and rises into the upper atmosphere, where both the pressure and the temperature are much lower. The balloon's skin stretches freely, so the gas inside is always at the same pressure as the air around it.
Table 1 — conditions at release and at maximum altitude Pressure / kPa Temperature / °C Volume / m³ At the ground 100 27 8.0 At maximum altitude 10 −53 to be found (c)
(3)Determine
Determine the volume of the balloon at maximum altitude, using Table 1.
A weather balloon is released from the ground and rises into the upper atmosphere, where both the pressure and the temperature are much lower. The balloon's skin stretches freely, so the gas inside is always at the same pressure as the air around it.
Table 1 — conditions at release and at maximum altitude Pressure / kPa Temperature / °C Volume / m³ At the ground 100 27 8.0 At maximum altitude 10 −53 to be found volume of the balloon = ............................ m³
(Total for Question 1 = 7 marks)
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(1)Which
Which quantity must be in kelvin when using p₁ ÷ T₁ = p₂ ÷ T₂?
Quantity A the pressure B the temperature C the volume D all three (Total for Question 2 = 1 mark)
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(1)State
State what must be kept constant for p₁V₁ = p₂V₂ to apply.
(Total for Question 3 = 1 mark)
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(3)Calculate
A gas at 150 kPa occupies 0.40 m³. It is compressed at constant temperature to 0.12 m³. Calculate its new pressure.
new pressure = ............................ kPa
(Total for Question 4 = 3 marks)
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(4)Calculate
A sealed rigid canister of gas is at 200 kPa at 27 °C. It is heated to 127 °C. Calculate the new pressure.
new pressure = ............................ kPa
(Total for Question 5 = 4 marks)
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(3)Explain
Explain why the temperature must be converted to kelvin before using p₁ ÷ T₁ = p₂ ÷ T₂.
(Total for Question 6 = 3 marks)
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(3)Determine
A diver's lungs hold 4.5 dm³ of air at a pressure of 300 kPa at depth. Determine the volume this air would occupy at the surface, where the pressure is 100 kPa, assuming the temperature does not change.
............................ dm³
(Total for Question 7 = 3 marks)
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(3)Suggest
Suggest why the pressure in the cylinder falls further than the pressure law alone predicts.
A cylinder in a cold store — A rigid gas cylinder is moved from a workshop at 27 °C into a cold store at −13 °C and left overnight. The pressure law predicts the pressure should fall from 500 kPa to about 433 kPa. The gauge reads 390 kPa the next morning. The cylinder's valve is old and the fitter has noticed a faint smell of gas near it.
(Total for Question 8 = 3 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 10 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain the Gas Laws to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Robert Boyle over three rounds, marked against descriptors you can read first.
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Back to the lesson
- The Gas Laws — Two equations that put numbers on everything the previous page explained.
- All of Incandio Physics · Incandio Exam Practice