CAIE A Level Chemistry 9701 · Polymerisation
Butane-1,4-diol and hexanedioic acid are heated together with a small amount of acid catalyst to form a polyester. Explain, in terms of the functional groups present, how this polyester is formed. Include the name of the linkage formed and the small molecule eliminated.
4 marks, so the mark scheme is looking for about 4 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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