| Date | May 2018 | Marks available | 2 | Reference code | 18M.3.hl.TZ2.5 |
| Level | HL | Paper | 3 | Time zone | TZ2 |
| Command term | Distinguish | Question number | 5 | Adapted from | N/A |
Question
Propene can polymerize to form polypropene.
Propene monomer: 
Distinguish between the manufacture of polyester and polyethene.
Markscheme
Any one of these alternatives:
ALTERNATIVE 1
Polyester: produced by condensation/esterification polymerization
Polyethene: produced by addition polymerization
ALTERNATIVE 2
Polyester: reaction between monomers/molecules containing two functional groups per molecule
Polyethene: reaction between monomers/molecules containing a carbon–carbon double bond/C=C
ALTERNATIVE 3
polyester polymerization forms a by-product/H2O
polyethene has no by-products/100% atom economy
Accept the names of different catalysts used for each polymerization as an alternative answer.
[2 marks]
Examiners report
[N/A]
