Edexcel A-Level Chemistry Paper 2, June 2024: Question 4

6 marks · Medium difficulty · Extended Writing

Discuss the role society and chemists can play in contributing to a more sustainable use and disposal of polymers, considering methods of dealing with waste polymers and how chemists limit the problems caused by their disposal.

Practise this question

Question

An extended response question worth 6 marks asking students to discuss the role of society and chemists in sustainable polymer use and disposal, with bullet points prompting consideration of waste polymer management and how chemists limit disposal problems, followed by lined writing space.
Question text

4 Discuss the role society, and chemists in particular, can play in order to contribute to

a more sustainable use of polymers.

Your answer should consider

• the different ways of dealing with waste polymers

• how chemists can limit the problems caused by the disposal of polymers.

(6)

… *P76896A01232*

(Total for Question 4 = 6 marks)

Mark scheme

Show the mark scheme A mark scheme showing a 6-mark levels of response rubric, allocating up to 4 marks for indicative content (IP1 to IP6 covering recycling, incineration, cracking, biodegradable polymers, and minimising toxic gas emissions) and up to 2 marks for structure and lines of reasoning.

Question

Answer Additional Guidance Mark

Number

*4 This question assesses the student’s ability to show a coherent and Guidance on how the mark scheme should be applied. (6)

logically structured answer with linkages and fully sustained The mark for indicative content should be added to the

reasoning. mark for lines of reasoning.

Marks are awarded for indicative content and for how the answer is For example, a response with five indicative marking

structured and shows lines of reasoning. points that is partially structured with some linkages

The following table shows how the marks should be awarded for and lines of reasoning scores 4 marks (3 marks for

indicative content. indicative content and 1 mark for partial structure and

some linkages and lines of reasoning).

Number of indicative marking Number of marks awarded for

points seen in answer indicative marking points If there were no linkages between the points, then the

64 same indicative marking points would yield an overall

5-4 3 score of 3 marks (3 marks for indicative content and no

3-2 2 marks for linkages).

00 In general it would be expected that 5 or 6 indicative

points would get 2 reasoning marks, and 3 or 4

The following table shows how the marks should be awarded for indicative points would get 1 mark for reasoning, and

structure and lines of reasoning. 0, 1 or 2 indicative points would score zero marks for

reasoning.

Number of marks awarded for If there is any incorrect chemistry, deduct mark(s) from

structure of answer and the reasoning. If no reasoning mark(s) awarded do not

sustained lines of reasoning deduct mark(s).

Answer shows a coherent 2

logical structure with linkages Comment: Look for the indicative marking points first,

and fully sustained lines of then consider the mark for the structure of the Answer

reasoning demonstrated and sustained line of reasoning.

throughout

Answer is partially structured 1

with some linkages and lines

of reasoning

Answer has no linkages 0

between points and is

unstructured

Indicative content

Treatment of waste polymers

IP1 (waste) polymers can be (sorted and) recycled Allow re-use / repurpose (objects made from)

polymers

IP2 (waste) polymers can be incinerated to release energy / Allow polymers can be incinerated to release heat

generate electricity / used as a fuel

IP3 (waste) polymers can be cracked / thermally Allow polymers can be used as a feedstock/raw

decomposed (to (re)form monomers) material for cracking

Allow polymers can converted into smaller / more

useful molecules (to be used as a feedstock)

Limiting problems caused by disposal

IP4 (chemists) develop / invent (new) biodegradable Allow use /develop / invent (new) polymers that

polymers decompose

Ignore use of alternative non-synthetic materials

Ignore biofuels

IP5 (chemists can help develop techniques to) minimise Allow minimise emissions of named pollutants

emission of harmful / toxic / acidic gases from from incineration e.g. HCl / SO2 / NOx / CO2 / CO

incineration (of waste polymers) / dioxins

Ignore comments on greenhouse gases / global

warming

IP6 by neutralising HCl / SO2 / NOx Allow by carbon capture of CO2

Allow by ensuring complete combustion to

minimise CO / by converting CO to CO2

(Total for Question 4 = 6 marks)

How to answer it

Sustainable Use and Disposal of Polymers

What this question tests

This is a 6-mark extended-response question testing your ability to recall industrial and chemical strategies for managing polymer waste (Indicative Content) and to structure a logical, sustained argument with clear scientific linkages (Reasoning Marks).

Question Breakdown & Mark Allocation

Edexcel A-Level Chemistry (6-mark Level of Response)

💡 Key Knowledge (Indicative Content - Up to 4 Marks)

  • IP1: Sorting and recycling / re-using polymer waste.
  • IP2: Incineration of waste polymers to release energy / generate electricity.
  • IP3: Cracking or thermal decomposition to re-form original monomers.
  • IP4: Developing new biodegradable polymers.
  • IP5 / IP6: Minimising and neutralising toxic emissions from incineration (e.g., scrubbing acidic gases like HCl or SO₂, carbon capture for CO₂).

🧠 Exam Technique (Structure & Reasoning - Up to 2 Marks)

  • Coherent Structure: Group your points logically (e.g., society's role in sorting/recycling first, followed by chemists' advanced technological solutions).
  • Linked Reasoning: Do not just list bullet points. Connect *why* a method is used or *how* chemists solve a disposal problem (e.g., explaining that PVC incineration produces HCl, which chemists neutralise using a base/scrubber).

✅ Model Answer Points (What examiners look for)

  • Society can actively sort and recycle plastic waste to prevent landfill build-up.
  • Waste polymers with high enthalpy of combustion can be incinerated safely to generate electricity.
  • Chemists can design thermal cracking processes to break down polymers into smaller, valuable molecules or original monomers for feedstock.
  • Chemists play a vital role by designing novel biodegradable polymers that break down naturally.
  • To manage harmful emissions from incineration (such as HCl from chlorinated plastics), chemists develop flue-gas scrubbers to neutralise acidic gases before release into the atmosphere.

❌ Common Errors & Pitfalls

  • Writing a list of unrelated facts: Failing to structure the answer logically results in losing both reasoning marks.
  • Vague chemistry: Saying "chemists clean up the smoke" instead of specifying the neutralisation of acidic gases (like HCl or SO₂) or carbon capture for CO₂.
  • Confusing recycling types: Mixing up mechanical recycling with feedstock recycling/cracking without clear definitions.
  • Ignoring societal vs chemical roles: Focusing entirely on industrial chemistry while forgetting society's role in sorting and local waste management.
Mark Scheme Award Rule: 5–6 points matched = 4 marks for indicative content. 3–4 points = 3 marks. To secure the full 2 reasoning marks, your answer must feature clear paragraph transitions linking society's practical waste management habits directly to the chemical innovations engineered to counteract disposal hazards.

Topics

Organic Chemistry · Topic 6: Organic Chemistry I

Question and mark scheme from the Edexcel A-Level Chemistry examination, Paper 2, June 2024. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.