AS Level Chemistry chapter 20: Polymerisation MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

22 exam-style questions on Polymerisation, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

22 questions · 1 topics · 10 per test

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What chapter 20 covers

Ten Polymerisation questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. A sample of poly(chloroethene) has an average Mr of 125 000. What is the average number of monomer units in one chain?

  1. A
    1000
  2. B
    2000
  3. C
    2577
  4. D
    4464
Show answer

Answer: B. Mr of CH2=CHCl = 2(12.0) + 3(1.0) + 35.5 = 62.5, and 125 000 ÷ 62.5 = 2000. 4464 uses ethene (28) instead of chloroethene; 1000 treats –CH2–CHCl–CH2–CHCl– as one unit.

2. Which statement about poly(ethene) and its monomer, ethene, is correct?

  1. A
    poly(ethene) has the same empirical formula as ethene
  2. B
    poly(ethene) is unsaturated, like ethene
  3. C
    poly(ethene) has the same Mr as ethene
  4. D
    poly(ethene) is formed with the loss of water
Show answer

Answer: A. Each ethene unit, C2H4, adds into the chain without losing any atoms, so the polymer is (CH2)n, empirical formula CH2, the same as ethene. The C=C bond is used up, so the polymer is saturated.

3. A section of a polymer chain is –CH2–CH2–CH2–CH(CH3)–CH2–CH2–CH2–CH(CH3)–. Which monomers were used?

  1. A
    propene only
  2. B
    ethene and but-1-ene
  3. C
    ethene and propene
  4. D
    but-1-ene only
Show answer

Answer: C. Split the backbone into two-carbon units: –CH2–CH2– (from ethene) alternating with –CH2–CH(CH3)– (from propene). Propene alone would put a CH3 on every second carbon; but-1-ene would give C2H5 side groups.

4. Why do poly(alkene)s such as poly(ethene) remain in landfill sites for a very long time?

  1. A
    they are biodegradable only in sunlight
  2. B
    they react slowly with water to form toxic products
  3. C
    they are made of chains that still contain C=C bonds
  4. D
    they are non-biodegradable, because their non-polar C–C and C–H bonds are not broken down by microorganisms
Show answer

Answer: D. Poly(alkene)s are saturated, non-polar chains, so they are chemically unreactive and are not attacked by bacteria or their enzymes. This persistence is the disposal problem.

5. Waste poly(ethene) is burned in an incinerator with a limited supply of air. Which harmful product is most likely to form?

  1. A
    carbon monoxide
  2. B
    hydrogen chloride
  3. C
    chlorine
  4. D
    sulfur dioxide
Show answer

Answer: A. Poly(ethene) contains only C and H, so incomplete combustion gives toxic carbon monoxide (and soot). Hydrogen chloride comes from burning PVC, not poly(ethene).

6. Which bond in each monomer molecule is broken when chloroethene, CH2=CHCl, polymerises?

  1. A
    the σ bond of the C=C double bond
  2. B
    the π bond of the C=C double bond
  3. C
    a C–H bond
  4. D
    the C–Cl bond
Show answer

Answer: B. Only the weaker π bond of C=C breaks; the σ bond stays, and each carbon uses the freed electron to bond to a neighbouring monomer. The Cl and H atoms stay on the chain.

7. What is the repeat unit of poly(propene)?

  1. A
    –CH2–CH2–CH2–
  2. B
    –CH2–CH(CH3)–
  3. C
    –CH(CH3)=CH–
  4. D
    –CH2–CH2–CH(CH3)–
Show answer

Answer: B. In addition polymerisation the C=C of the monomer opens to a C–C single bond and every atom is kept. Propene, CH2=CHCH3, gives –CH2–CH(CH3)–; the methyl group hangs off the backbone rather than joining it.

8. Which statements about poly(ethene) and poly(chloroethene) are correct?
1 Both polymers are saturated.
2 Both are formed by addition with no other product.
3 Only poly(chloroethene) has permanent dipole–permanent dipole forces between its chains.

  1. A
    1 and 2 only
  2. B
    2 and 3 only
  3. C
    1, 2 and 3
  4. D
    1 only
Show answer

Answer: C. Both chains contain only single bonds and form with no by-product. The polar C–Cl bonds in poly(chloroethene) give permanent dipole–dipole forces between chains; poly(ethene) has only instantaneous dipole forces.

9. What is the repeat unit of the polymer formed from propenenitrile, CH2=CHCN?

  1. A
    –CH2–CH(CN)–
  2. B
    –CH2–CH2–CN–
  3. C
    –CH=C(CN)–
  4. D
    –CH2–C(CN)=CH–
Show answer

Answer: A. The C=C opens and the CN group stays as a side group on the chain: –CH2–CH(CN)–. The chain is saturated, so options with C=C are wrong, and CN is not part of the backbone.

10. What is the repeat unit of the polymer formed from 2-methylbut-2-ene, (CH3)2C=CHCH3?

  1. A
    –CH2–C(CH3)2–CH2–CH2–
  2. B
    –C(CH3)2–CH2–CH2–
  3. C
    –CH(CH3)–CH(CH3)–CH2–
  4. D
    –C(CH3)2–CH(CH3)–
Show answer

Answer: D. Only the two carbons of the C=C go into the backbone; every other carbon stays as a CH3 side group. The repeat unit has two backbone carbons, carrying two methyl groups and one methyl group.

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How many Polymerisation MCQs are there?

22, each with the answer and a short explanation, across 1 topics: Addition polymerisation. Every chapter test draws ten of them, so you can take it many times.

Is the AS Level Chemistry chapter 20 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

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