1. X with 2,4-DNPH forms a red precipitate. 2. X reduces blue Copper ions into red precipitate. What kind of compound is X?

X with 2,4 DNPH (Brady's reagent) is used to show the presence of an aldehyde or ketone. X also reduces Copper ions (Fehling's) meaning it has to be an aldehyde and not a ketone as ketones are not readily oxidisable. A positive Brady's test will form a yellow, orange or red precipitate. A yellow precipitate indicates an aliphatic compound whereas a red one indicates an aromatic compound (i.e. a benzene ring). As Brady's reagent caused a red precipitate and we know it is an aldehyde, we can assume it is a structure like Benzaldehyde (i.e. aldehyde with aromatic compound).

TA

Related Chemistry A Level answers

All answers ▸

How do you go about answering titration equations?


Describe how propenal, propanal and propanone can be distinguished from one another by simple chemical tests.


Name and draw the mechanism where bromoethane reacts with NaOH to form ethanol.


Explain the 3 pieces of evidence that disprove Kekule's model of benzene.