Molisch test is Specific to all carbohydrates — It is used to differentiate between Proteins & Amino Acids (-ve), and Carbohydrates (+ve). The Molisch reagent reacts with all carbohydrates larger than tetroses. This test is based on the fact that pentoses and hexoses are dehydrated by conc. H2SO4 acid to form furfural or hydroxymethylfurfural, respectively, which forms a reddish violet ring at the interface of the two solutions.