AQA GCSE Chemistry Chemistry Paper 2 (Higher), 2024: Question 6

11 marks · Standard Demand difficulty · Extended Answer

Evaluate the use of aluminium alloy and bamboo for bicycle frames, explain why aluminium resists corrosion, suggest a method to protect bicycle chains from rusting, and identify the roles of carbon fibre and polymer resin in a composite material.

Practise this question

Question

A multipart chemistry question about bicycle materials. It includes an image of a bicycle, a table comparing aluminium alloy and bamboo across categories like cost, strength, mass, lifespan, and disposal, followed by four sub-questions (06.1 to 06.4) requiring evaluation, explanation, suggestion, and identification of composite components.
Question text

06 This question is about materials used to make bicycles.

Figure 6 shows a bicycle.

Figure 6

Table 3 shows information about two materials used to make bicycle frames.

Table 3

Material

Aluminium alloy Bamboo

Raw material aluminium ore bamboo plant

Cost of frame in £ 250 1500

Strength in arbitrary units 290 193

Mass in kilograms 1.6 2.4

Lifespan in years 6–10 10–15

One method of disposal recycled to make new burned to produce heat

at end of life 23products energy

06.1 Evaluate the use of aluminium alloy and of bamboo for making bicycle frames.

Use Table 3.

[6 marks]

06.2 Explain why aluminium alloy bicycle frames do not need protection from corrosion.

[2 marks]

06.3 Bicycle chains are made from an alloy of iron.

Bicycle chains rust without protection.

Paint is not used to protect bicycle chains from rusting.

Suggest how bicycle chains can be protected from rusting.

[1 mark]

06.4 Bicycle frames can also be made from a composite of carbon fibres embedded in a

polymer resin.

What description is given in this composite to:

• the carbon fibre component

• the polymer resin component?

[2 marks]

Carbon fibre

Polymer resin

Mark scheme

Show the mark scheme The mark scheme provides a level-based rubric for the 6-mark evaluation question, listing indicative content such as renewability, cost, strength, mass, and disposal methods. It also provides specific marking points for the remaining questions: explaining the aluminium oxide layer, suggesting grease for chains, and identifying carbon fibre as reinforcement and polymer resin as the matrix/binder.

Question 6

AO /

Question Answers Mark

Spec. Ref.

06.1 Level 3: A judgement, strongly linked and logically supported by a 5–6 AO3

sufficient range of correct reasons, is given. 4.10.2.1

4.10.3.2

Level 2: Some logically linked reasons are given. There may also 3–4

be a simple judgement.

Level 1: Relevant points are made. They are not logically linked. 1–2

No relevant content 0

Indicative content 1

• bamboo is renewable

• aluminium is a finite resource

• growing bamboo uses up agricultural land

• mining aluminium ore is a polluting activity

• cost of aluminium alloy is lower

• (so) can be replaced more frequently

• aluminium alloy is stronger

• (so) can withstand larger forces

• aluminium alloy has lower mass

• (so) bicycle is faster

• (so) is easier to carry / transport

• the aluminium alloy frame lasts less long

• (so) bicycle must be replaced more frequently

• aluminium alloy is recyclable (so) aluminium ores are conserved

• bamboo can provide renewable heat energy

• (so) less overall contribution to global warming

• (and) is carbon neutral

• neither material may reach landfill

• both materials have a sustainable disposal method

Reasoned judgment – – –

AO /

Question Answers Extra information Mark 21

Spec. Ref.

06.2 aluminium (alloy) has an oxide 1 AO1

coating 4.10.3.1

(so) contact between aluminium do not accept sacrificial 1

(alloy) and water / air / oxygen is protection

prevented

AO /

Question Answers Extra information Mark

Spec. Ref.

06.3 (coating with) grease allow (coating with) oil 1 AO2

allow galvanise 4.10.3.1

allow use stainless steel as the

alloy

AO /

Spec. Ref.

06.4 (carbon fibre) reinforcement allow reinforces the polymer / 1 AO2

resin 4.10.3.3

ignore (carbon) fibres

(polymer resin) matrix / binder allow binds the fibres / 1

fragments

ignore (polymer) resin

Total Question 6 11

How to answer it

Bicycle Materials: Alloys, Composites, and Corrosion

What this question tests

This question assesses your ability to evaluate data to make a reasoned judgment, your understanding of corrosion prevention in metals, and your knowledge of the structure of composite materials.

Part 06.1

Evaluating Materials for Bike Frames

6 Marks - Level of Response

🧠 Exam Technique

For a 6-mark "Evaluate" question, you must:

  • Compare both materials.
  • Use the data provided in the table.
  • Explain the consequence of the data (e.g., "lower mass means the bike is faster").
  • Give a reasoned judgment (conclusion) at the end.

💡 Key Knowledge

  • Finite: Will run out (e.g., metal ores).
  • Renewable: Can be replaced at the rate they are used (e.g., plants).
  • Carbon Neutral: The CO₂ released when burned is equal to the CO₂ absorbed while growing.

✅ Model Answer Points

  • Sustainability: Bamboo is renewable and carbon neutral when burned for energy. Aluminium ore is finite and mining it causes pollution.
  • Performance: Aluminium alloy is stronger (290 vs 193) so it can withstand larger forces. It also has a lower mass (1.6kg vs 2.4kg), making the bike faster or easier to carry.
  • Cost & Life: Aluminium is much cheaper (£250 vs £1500), though it has a shorter lifespan (6–10 years vs 10–15 years).
  • End of Life: Both are sustainable; aluminium is recycled (conserving ore), while bamboo provides heat energy.
  • Conclusion: Aluminium is better for performance and budget, whereas bamboo is better for long-term sustainability and durability.
Examiner Insight: To reach Level 3 (5-6 marks), you must link the facts to a logical reason. Don't just say "Aluminium is lighter." Say "Aluminium is lighter, so the bicycle is easier to transport."
Part 06.2

Aluminium and Corrosion

2 Marks

✅ Correct Answer

  1. Aluminium has a protective oxide coating.
  2. This prevents oxygen and water from reaching the metal underneath.

❌ Common Errors

  • Saying "Aluminium is unreactive" (It is actually quite reactive!).
  • Claiming it uses "sacrificial protection" (This is for galvanised steel).
Part 06.3

Protecting Iron Chains

1 Mark

🧠 Read the Question!

The question explicitly states "Paint is NOT used." If you write "paint," you will get 0 marks even though paint does stop rust.

✅ Accepted Answers

  • Coat with grease or oil (best for moving parts like chains).
  • Galvanising (coating in zinc).
  • Use stainless steel (an alloy that doesn't rust).
Part 06.4

Composite Materials

2 Marks

💡 Key Knowledge

Most composites are made of two main parts:

  • The Reinforcement: Fibres or fragments that provide the strength.
  • The Matrix: The material that surrounds and binds the reinforcement together.

✅ Correct Labels

  • Carbon fibre: Reinforcement
  • Polymer resin: Matrix (or binder)
Examiner Insight: Students often swap these. Remember: the "fibres" are what reinforce the structure, like steel bars in concrete.

Topics

Chemistry

Question and mark scheme from the AQA GCSE Chemistry examination, Chemistry Paper 2 (Higher), 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.