CAIE A Level Chemistry 9701 · Carbonyl compounds
A student has two unlabelled samples, one of butanone and one of butanal. Describe how the student could use the reaction with alkaline iodine (iodoform test) and the reaction with Tollens' reagent to distinguish between the two compounds. In your answer, state the observations for each compound with each reagent, and explain the difference in the outcome of the iodoform test.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.