CAIE A Level Chemistry 9701 · Organic synthesis
A student claims that propene can be converted to 3-hydroxybutanal ((OH)) in two steps.
Step 1: Propene is treated with steam and phosphoric acid at 300°C and 60 atm, forming compound X. Step 2: Compound X is heated under reflux with acidified potassium dichromate(VI).
Explain why the product of Step 2 is propanone, and not 3-hydroxybutanal, and state the type of reaction for each step.
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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