Addition polymers and polymer disposalEdexcel A-Level Chemistry: Subtopic test

1. 1
   Poly(chloroethene), commonly called PVC, is an addition polymer used to make window frames and drainpipes.

   (a)

   What is the monomer used to make poly(chloroethene)?

   [1 mark]

   • ACH₃CH=CH₂
   • BCH₂=CCl₂
   • CCH₂=CHCl
   • DClCH=CHCl

   (b)

   Which is the repeat unit of poly(chloroethene)?

   [1 mark]

   • A–CH₂=CHCl–
   • B–CH₂–CHCl–
   • C–CH₂–CH₂–Cl–
   • D–CHCl–CHCl–

   (c)

   A sample of PVC has a relative molecular mass of 125 000. Calculate the number of repeat units in each polymer chain. (Ar: H = 1.0, C = 12.0, Cl = 35.5)

   [2 marks]

   Total for question 1: 4 marks

2. 2
   A packaging company makes crates from poly(propene). A section of the polymer chain is drawn as –CH₂–CH(CH₃)–CH₂–CH(CH₃)–CH₂–CH(CH₃)–.

   (a)

   Which monomer forms the polymer in the section of chain shown?

   [1 mark]

   • ABut-1-ene
   • BEthene
   • CPropane
   • DPropene

   (b)

   Why are crates made from poly(propene) slow to break down in landfill?

   [1 mark]

   • AThe saturated chain has strong non-polar bonds that micro-organisms cannot easily break down
   • BThe chain contains C=C bonds that micro-organisms cannot attack
   • CThe polymer reacts with rain water to form a strong acid
   • DThe monomer is made from crude oil, and substances from crude oil cannot ever be broken down

   (c)

   Waste poly(propene) crates are burned in an incinerator with plenty of air. Write a balanced equation for the complete combustion of poly(propene), using C₃H₆ for the repeat unit, and state one advantage of incineration.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A waste-treatment company incinerates mixed plastic waste, which includes poly(chloroethene), PVC, in order to generate electricity.

   (a)

   Name the toxic gas formed when the PVC is burned that is not formed when poly(propene) is burned, and explain why it forms. Describe how the gas can be removed from the waste gases.

   [3 marks]

   (b)

   The company burns 1.00 kg of PVC. Assuming all the chlorine in the PVC is converted to hydrogen chloride, calculate the mass of hydrogen chloride formed. (Ar: H = 1.0, C = 12.0, Cl = 35.5)

   [4 marks]

   Total for question 3: 7 marks

4. 4
   A supermarket chain is replacing its single-use carrier bags, which are made from poly(ethene), a polymer made from crude oil. It is comparing recycling, incineration and bags made from a biodegradable polymer.

   (a)

   Evaluate the options of recycling, incineration and biodegradable bags for dealing with the waste carrier bags.

   [6 marks]

   (b)

   Explain how chemists can contribute to more sustainable use of polymers such as poly(ethene), in terms of energy and resources, over the whole life cycle of a carrier bag.

   [6 marks]

   Total for question 4: 12 marks

End of questions