AQA GCSE Physics Physics Paper 1 (Foundation), November 2021: Question 8
8 marks · Standard Demand difficulty · Short Answer
Investigate the relationship between the pressure and volume of a gas using a syringe and pressure gauge apparatus, including determining range, completing sentences on conditions, calculating constants and new pressures, and identifying particle behavior.
Practise this questionQuestion
Question text
08 A teacher demonstrated the relationship between the pressure in a gas and the
volume of the gas.
Figure 12 shows the equipment used.
Figure 12
08.1 What is the range of the syringe?
[1 mark]
Tick ( ) one box.
From 0 to 1 cm3
From 0 to 5 cm3
From 0 to 25 cm3
08.2 The relationship between the pressure and volume of a gas is given by the equation:
pressure × volume = constant
Complete the sentence.
[1 mark]
For this equation to apply, both the mass of gas and the
of the gas must stay the same.
08.3 The initial volume of the gas in the syringe was 12 cm3.
The initial pressure of the gas in the syringe was 101 000 Pa.
Calculate the constant in the equation below.
pressure × volume = constant
[2 marks]
Constant = Pa cm3
08.4 The teacher pulled the plunger slowly outwards and the gas expanded.
The new volume of the gas was 24 cm3.
Calculate the new pressure in the gas.
The constant has the same value as in Question 08.3
[3 marks]
New pressure = Pa
08.5 Which change occurs when the plunger is pulled slowly outwards?
[1 mark]
Tick ( ) one box.
The gas particles stop moving.
There are more frequent collisions between the gas particles.
There is more space between the gas particles.
Mark scheme
Show the mark scheme
Question 8
AO /
Question Answers Extra information Mark
Spec. Ref.
08.1 0 to 25 cm3 1 AO2
4.3.3.2
08.2 temperature 1 AO1
4.3.3.2
08.3 101 000 × 12 = constant 1 AO2
4.3.3.2
constant = 1 212 000 (Pa cm3) 1
08.4 p × 24 = 1 212 000 allow ecf from question 08.3 1 AO2
4.3.3.2
1 212 000 1
p =
p = 50 500 (Pa)
08.5 there is more space between 1 AO1
the gas particles 4.3.3.2
Total 8
How to answer it
Pressure and Volume of a Gas Study Guide
This question assesses your understanding of the particle model of matter, specifically how the pressure and volume of a gas are inversely related at a constant temperature (Boyle's Law). You will need to interpret scientific equipment scales, recall conditions required for gas laws, perform multi-step calculations using pressure × volume = constant , and explain gas behaviour using particle theory.
Reading Equipment Scales
What is the range of the syringe?
✅ Correct Answer
From 0 to 25 cm³ (Ticked)
💡 Key Knowledge
- The range of an instrument is the span between its minimum and maximum possible readings.
- Looking at Figure 12, the syringe scale starts at 0 and goes up to a maximum value of 25 cm³.
Conditions for Gas Equations
Complete the sentence: For this equation to apply, both the mass of gas and the ________ of the gas must stay the same.
✅ Correct Answer
temperature
💡 Key Knowledge
- Boyle's Law ( pressure × volume = constant ) only holds true under constant temperature and when no gas escapes (constant mass/number of moles).
- If temperature changes, particle speed changes, altering the pressure independently of volume changes.
Calculating the Constant
The initial volume is 12 cm³ and pressure is 101 000 Pa. Calculate the constant.
📐 Step-by-Step Calculation
- Identify the equation: pressure × volume = constant
- Substitute the values: 101 000 × 12 = constant
- Calculate: 1 212 000
Constant = 1 212 000 Pa cm³
❌ Common Errors & Examiner Insights
- Students sometimes forget to include the correct units or misread standard scientific notation.
- Make sure you show your working out clearly so examiners can award method marks even if a minor arithmetic slip occurs.
Calculating New Pressure
The plunger is pulled outwards to a new volume of 24 cm³. Calculate the new pressure.
📐 Step-by-Step Calculation
- State the relationship: p × v = constant (1 212 000 from 08.3)
- Substitute knowns: p × 24 = 1 212 000 (Allow ECF if 08.3 was incorrect)
- Rearrange and solve: p = 1 212 000 / 24
- Final Answer: p = 50 500 Pa
🧠 Exam Technique
- Notice how doubling the volume (from 12 cm³ to 24 cm³) halves the pressure (from 101 000 Pa down to 50 500 Pa). Use this inverse relationship as a quick mental check!
- ECF (Error Carried Forward): If you got 08.3 wrong, use your incorrect constant here to secure the substitution and calculation marks.
Explaining Gas Expansion
Which change occurs when the plunger is pulled slowly outwards?
✅ Correct Answer
There is more space between the gas particles. (Ticked)
❌ Common Errors & Misconceptions
- Students often incorrectly select "more frequent collisions" — pulling the plunger outwards increases the volume, meaning particles are spread further apart, leading to less frequent collisions (which explains why the pressure drops!).
- Particles themselves do not expand or stop moving; only the space between them increases.
Topics
Physics · P3: Particle Model of Matter
Question and mark scheme from the AQA GCSE Physics examination, Physics Paper 1 (Foundation), November 2021. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.