CAIE A Level Chemistry 9701 · Carbonyl compounds
A student is given a colourless liquid that is known to be a carbonyl compound. Describe how the student could confirm the presence of a carbonyl group using 2,4-dinitrophenylhydrazine (2,4-DNPH) reagent, and state the observation that would be made.
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.
Describe means: Say what happens or what something is like, in order and with detail. You are not being asked why. If there is data, quote it: name the trend, then give figures with units at the points where it changes.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.