CAIE A Level Chemistry 9701 · Organic synthesis
A student plans to prepare 2-hydroxybutanenitrile, , starting from propanal, , and hydrogen cyanide.
The route is:
Step 1: propanal is warmed with an aqueous solution of sodium cyanide and a small amount of dilute sulfuric acid.
Step 2: the product of Step 1 is separated and purified.
Explain what happens in Step 1, including the type of reaction and the role of the dilute sulfuric acid.
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.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.