Tollen’s Test for Aldehydes and Ketones
Tollen’s Reagent is added to two flasks. A dextrose water solution is added to one and swirled. The contents of the flask turn brown and then silver is plated onto the inside of the flask. Sucrose is added to the other flask. The contents may turn brown but no silver is plated.
Silver (I) is reduced to silver metal by aldehydes but not by ketones.