The mild oxidising agents given below are used to distinguish
aldehydes from ketones:
(i) Tollens’ test:  On warming an aldehyde with freshly prepared
ammoniacal silver nitrate solution (Tollens’ reagent), a bright
silver mirror is produced due to the formation of silver metal The aldehydes are oxidised to corresponding carboxylate anion The reaction occurs in alkaline medium (ii) Fehling’s test: Fehling reagent comprises of two solutions,
Fehling solution A and Fehling solution B