Both aldehydes and ketones contain the carbonyl group,
In aldehydes a hydrogen atom is bonded to the carbonyl group but in ketones the carbonyl group is always flanked by carbon atoms: this structural difference accounts for the fact that aldehydes can undergo mild oxidation to form carboxylic acids but ketones resist oxidation. Oxidising agents can therefore be used to distinguish between aldehydes and ketones.
The aim of this experiment is to use the mild oxidising agents, acidified potassium dichromate solution, Benedict’s solution and Tollens’ reagent, to distinguish between two given carbonyl compounds one of which is an aldehyde and the other a ketone.
Identifying Carbonyls – Pupil Guide
