Acetone and propanal can be distinguished by

Acetone and propanal are Functional isomers can be distinguished by Tollen’s reagent.

Acetone and propanal are both carbonyl-containing compounds, but they have distinct functional groups that can be used to differentiate them. Acetone is a ketone (a carbonyl group attached to two alkyl groups), while propanal is an aldehyde (a carbonyl group attached to at least one hydrogen atom).

To distinguish between the two, we can us Tollen’s Reagent, which is a solution of silver nitrate in ammonia. Tollen’s Reagent reacts with aldehydes but not with ketones. When Tollen’s reagent is added to an aldehyde like propanal, it gets reduced to silver, forming a silver mirror on the inner surface of the test tube. This reaction does not occur with acetone since it is a ketone and lacks the reactive hydrogen attached to the carbonyl carbon.

Thus, Tollen’s Reagent can be used to differentiate acetone (which does not react) from propanal (which reacts, giving a silver mirror).