Edexcel A-Level Chemistry Paper 2, June 2022: Question 1
4 marks · Medium difficulty · Multiple Choice
Identify polymer repeat units, waste disposal methods, and sustainable chemistry principles in multiple-choice questions.
Practise this questionQuestion
Question text
1 This is a question about polymers.
(a) An addition polymer is formed from 2-methylpent-2-ene.
What is the repeat unit for poly(2-methylpent-2-ene)?
(1)
A B
C D
(b) Which is not a use of waste poly(alkenes)?
(1)
A feedstock for cracking
B generation of biodegradable materials
C incineration to release energy
D make new materials by recycling
(c) A condensation polymer can be made from ethane-1,2-diol and butanedioic acid.
Which is the repeat unit for this polymer?
(1)
A B
O O O O
O (CH2)2 O C (CH2)2 C O O (CH2)2 O C (CH2)2 C
2 C D
O*P67094RA0224*O O O
O (CH2)2 O C (CH2)4 C O O (CH2)2 O C (CH2)4 C
(d) Which approach used by chemists would not contribute to a more sustainable
use of materials over the life cycle of a polymer?
(1)
A make more efficient use of energy
B make more efficient use of resources
C use catalysts for a faster reaction rate
D use a higher temperature for a faster reaction rate
(Total for Question 1 = 4 marks)
Mark scheme
Show the mark scheme
Question
Answer Mark
Number
1(a) (1)
The only correct answer is A ( )
B is not correct because there is no C=C in the repeat unit
C is not correct because the extension bonds are not from the correct carbon atoms of the chain and
there should not be a C=C in the repeat unit
D is not correct because the extension bonds are not from the correct carbon atoms of the chain
Question
Answer Mark
Number
1(b) The only correct answer is B (generation of biodegradable materials) (1)
A is not correct because some poly(alkenes) may be used as a feedstock for cracking
C is not correct because some poly(alkenes) may be used for energy from incineration
D is not correct because some poly(alkenes) may be used for recycling to make new materials
Question
Answer Mark
Number
1(c) (1)
The only correct answer is B ( )
A is not correct because there is an additional oxygen atom in the repeat unit
C is not correct because there is an incorrect number of CH2 groups in one of the monomers and there is
an additional oxygen atom in the repeat unit
D is not correct because there is an incorrect number of CH2 groups in one of the monomers
Question
Answer Mark
Number
1(d) The only correct answer is D (use a higher temperature for a faster reaction rate) (1)
A is not correct because efficient use of energy does contribute to sustainability
B is not correct because efficient use of resources does contribute to sustainability
C is not correct because use of catalysts do contribute to sustainability
(Total Question 1 = 4 marks)
How to answer it
Edexcel A-Level Chemistry: Polymers & Sustainability Study Guide
This 4-mark multiple-choice sequence assesses your understanding of polymer chemistry, specifically distinguishing between addition and condensation polymerisation repeat units, identifying properties and disposal methods of waste poly(alkenes), and evaluating green chemistry principles related to the industrial lifecycle sustainability of materials.
Part (a) — Addition Polymer Repeat Units
Question 1(a): Finding the repeat unit for poly(2-methylpent-2-ene)
✅ Correct Answer: A
Option A is correct. When drawing addition polymer repeat units, the double bond of the monomer (C=C) opens up into a single bond (C-C), and the extension bonds break through the square brackets to show continuity.
❌ Common Errors
- Option B: Incorrectly retains the C=C double bond inside the repeat unit.
- Option C: Places the extension bonds across the wrong carbons, leaving the backbone incorrectly structured.
- Option D: Fails to remove the double bond entirely and connects through incorrect carbon positions.
Part (b) — Waste Poly(alkenes)
Question 1(b): Identifying non-uses of waste poly(alkenes)
✅ Correct Answer: B
Option B (generation of biodegradable materials) is correct. Standard poly(alkenes) like poly(ethene) or poly(propene) possess a completely non-polar saturated hydrocarbon backbone, making them chemically inert and non-biodegradable.
💡 Key Knowledge
Poly(alkenes) are disposed of or managed industrially via:
- Acting as a feedstock for cracking into smaller, useful molecules.
- Incineration to harvest thermal energy release.
- Mechanical recycling to remould into new commercial items.
Part (c) — Condensation Polymerisation
Question 1(c): Condensation polymer from ethane-1,2-diol and butanedioic acid
✅ Correct Answer: B
Option B correctly reflects the ester linkage formation. Ethane-1,2-diol provides a -O-(CH₂)₂-O- group, while butanedioic acid provides a -C(=O)-(CH₂)₂-C(=O)- group.
🧠 Exam Technique
Count your carbon chains carefully! Butanedioic acid contains a total of 4 carbons ( -C(=O)-(CH₂)₂-C(=O)- ), meaning there are 2 carbons in the central alkane chain segment. Check the length of the hydrocarbon chain blocks before choosing between options containing (CH₂)₂ and (CH₂)₄ .
Part (d) — Green Chemistry & Sustainability
Question 1(d): Sustainable approaches across a polymer lifecycle
✅ Correct Answer: D
Option D (use a higher temperature for a faster reaction rate) is the correct choice because burning extra fossil fuels or electrical energy to drive up reaction temperatures worsens the environmental footprint and reduces overall energy efficiency, conflicting with sustainability goals.
❌ Avoid This Trap
Remember that options A, B, and C do contribute positively to sustainability: efficient energy use cuts emissions, resource efficiency reduces waste, and catalysts lower activation energy requirements so reactions proceed rapidly at milder temperatures.
Topics
Organic Chemistry · Topic 6: Organic Chemistry I · Topic 17: Organic Chemistry II
Question and mark scheme from the Edexcel A-Level Chemistry examination, Paper 2, June 2022. QuestionVault is an independent revision resource; questions remain the copyright of the awarding body.