AQA GCSE Chemistry Chemistry Paper 2 (Higher), 2022: Question 3

9 marks · Standard Demand difficulty · Extended Answer

Evaluate the use of glass versus polymer for milk bottles using life cycle assessment data, and calculate the mass of a cardboard carton using density and volume.

Practise this question

Question

An exam page showing Question 3. Question 3.1 presents Table 2, comparing glass and polymer milk bottles across raw materials, energy to process raw materials (6750 kJ vs 1710 kJ), energy to manufacture (750 kJ vs 90 kJ), mass (200 g vs 20 g), mean lifetime uses (25 vs 1), and disposal (both recycled). It asks to evaluate the use of glass compared to polymer for milk bottles using LCAs and Table 2. Question 3.2 states a cardboard carton has a volume of 40 cm³ and density of 0.40 g/cm³, and asks to calculate the mass using the equation density equals mass divided by volume.
Question text

03 This question is about life cycle assessments (LCAs).

03.1 Milk bottles can be made from glass or from a polymer.

Table 2 shows information about milk bottles of equal volume.

Table 2

Glass Polymer

Limestone

Raw materials Sand Crude oil

Sodium carbonate

Energy needed to process raw

6750 1710

materials in kilojoules

Energy needed to

750 90

manufacture bottle in kilojoules

Mass of bottle in grams 200 20

Mean number of times used

25 1

during lifetime of bottle

One disposal method at end Recycled to make Recycled to make

of useful life different glass products different polymer products

Evaluate the use of glass for milk bottles compared with the use of a polymer for

milk bottles.

Use features of life cycle assessments (LCAs) in your answer.

Use Table 2.

[6 marks]

03.2 Milk is also sold in cardboard cartons.

A carton is made using 40 cm3 of cardboard.

The density of the cardboard is 0.40 g/cm3.

Calculate the mass of the carton.

Use the equation:

mass

density =

volume

[3 marks]

Mass = g

Mark scheme

Show the mark scheme The mark scheme for Question 3. For 3.1, a level-based mark scheme (1 to 6 marks) is shown with indicative content categorized by raw materials, manufacturing, use and operation, disposal, other points, and reasoned judgment. For 3.2, it shows the 3-mark calculation: mass equals density times volume, mass equals 0.40 times 40, leading to the final answer of 16 grams.

Question 3

AO /

Question Answers Mark

Spec. Ref

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

sufficient range of correct reasons, is given. 4.10.1.1

4.10.2.1

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

raw materials

• crude oil is finite

• quarrying / mining pollute the environment

• glass uses more energy to process raw materials

manufacturing

• glass uses more energy to make bottles

• glass is heavier so takes more energy to transport

use and operation

• glass bottles are reusable

• reuse of glass conserves (natural) resources

• reuse of glass consumes energy during washing

• reuse of glass consumes water during washing

disposal

• both glass and polymer bottles can be recycled

• recycling polymer conserves finite resources

• recycling glass and polymer uses less energy than making new

glass and polymer

• both methods reduce use of landfill

other points

• energy needed may be derived from fossil fuels

• use of fossil fuels causes (specified) pollution

• total energy for glass (bottle) (7500 kJ) is greater than total

energy for polymer (bottle) (1800 kJ)

reasoned judgement

12 AO /

Question Answers Extra information Mark

Spec. Ref.

03.2 mass = density × volume 1 AO2

4.10.1.1

mass = 0.40 × 40 1 4.10.2.1

= 16 (g) 1

Total Question 3 9

How to answer it

Life Cycle Assessments & Density Calculations

What this question tests

This question assesses your ability to evaluate environmental impacts using Life Cycle Assessments (LCAs) by comparing data from a table, structuring a balanced comparison, and writing a reasoned conclusion. It also tests your basic numeracy skills in rearranging and solving a density, mass, and volume calculation.

Part (a) - Question 3.1

Evaluating Glass vs. Polymer Milk Bottles

6 Marks Extended Writing / Evaluation

You are asked to evaluate the use of glass compared to polymer for milk bottles using Table 2 and your knowledge of LCAs. To get full marks, you must structure your answer around the stages of an LCA and provide a clear, reasoned judgement.

💡 Key Knowledge: LCA Stages

A Life Cycle Assessment (LCA) looks at the environmental impact of a product across 4 main stages:

  • 1. Extracting & processing raw materials: Are they finite (crude oil) or renewable? Does mining/quarrying damage habitats?
  • 2. Manufacturing & packaging: How much energy is consumed?
  • 3. Use & operation during lifetime: Can the product be reused?
  • 4. Disposal at the end of life: Can it be recycled, or does it go to landfill?

🧠 How to Structure a 6-Mark Evaluation

To score 5-6 marks (Level 3), you must organize your points logically and include a final conclusion:

  • Compare both materials at each stage of their life cycle.
  • Use the data: Don't just copy numbers; explain what they mean (e.g., "Glass is heavier, which means more fuel is needed for transport").
  • Give a reasoned judgement: State clearly which material is better overall and justify why.

✅ Model Answer Structure

Your answer should cover these key areas:

LCA Stage Glass Bottles Polymer Bottles
Raw Materials Made from limestone, sand, and sodium carbonate. Quarrying these can damage ecosystems, but they are relatively abundant. Processing uses a lot of energy (6750 kJ). Made from crude oil, which is a finite resource (will run out). Processing uses much less energy (1710 kJ).
Manufacturing Uses more energy to manufacture (750 kJ). Glass is much heavier (200 g vs 20 g), meaning more fuel and energy are needed to transport them. Uses very little energy to manufacture (90 kJ). They are lightweight (20 g), making transport highly energy-efficient.
Use & Reuse Highly reusable (used an average of 25 times). This conserves raw materials but consumes water and energy for washing. Single-use only (used 1 time). This means new bottles must constantly be manufactured.
Disposal Can be recycled to make new glass products, reducing landfill. Can be recycled to make different polymer products, conserving crude oil.

Reasoned Judgement (Example): Overall, glass is better because it can be reused 25 times, which conserves natural resources and reduces waste, despite its higher initial energy cost for manufacturing and transport.

Mark Scheme Breakdown:
• Level 3 (5-6 marks): A clear, balanced comparison across multiple stages with a logical, supported final judgement.
• Level 2 (3-4 marks): Good comparative points are made, but lacks a clear final judgement or misses some LCA stages.
• Level 1 (1-2 marks): Simple, unlinked facts copied directly from the table.

❌ Common Pitfalls to Avoid

  • No conclusion: Many students write excellent comparisons but forget to write a final sentence stating which bottle is better overall. This immediately caps your mark!
  • Copying without explaining: Writing "Glass weighs 200g and polymer weighs 20g" gets little credit. You must explain the impact: "Glass is heavier, so it requires more fuel/energy to transport."
  • Ignoring reuse: Forgetting to mention that glass can be reused 25 times, which offsets its high manufacturing energy.

Part (b) - Question 3.2

Calculating the Mass of a Cardboard Carton

3 Marks Calculation

Calculate the mass of a cardboard carton with a volume of 40 cm³ and a density of 0.40 g/cm³ .

📐 Step-by-Step Solution

Step 1: Identify the given values and the formula

The question gives you the formula: density = mass / volume

  • Density = 0.40 g/cm³
  • Volume = 40 cm³

Step 2: Rearrange the formula to find mass

To isolate mass, multiply both sides by volume:

mass = density × volume (1 Mark)

Step 3: Substitute the numbers into the equation

mass = 0.40 × 40 (1 Mark)

Step 4: Calculate the final answer

mass = 16 g (1 Mark)

❌ Calculation Traps

  • Incorrect Rearrangement: Students often incorrectly rearrange the formula to mass = density / volume or mass = volume / density . Remember the formula triangle: Mass is on top, Density and Volume are on the bottom.
  • Not showing working: Even if you make an arithmetic error, showing mass = density × volume secures you 1 mark. Always write down your rearranged formula!

Topics

Chemistry · C10: Using Resources

Question and mark scheme from the AQA GCSE Chemistry examination, Chemistry Paper 2 (Higher), 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.