A student is provided with two unlabeled test tubes containing aqueous solutions of D-glucose and D-fructose. Which of the following reagents can be used to successfully distinguish between the two sugars?

Step-by-step solution

Tollen's reagent, Fehling's solution, and Benedict's solution are all basic in nature. In an alkaline medium, D-fructose undergoes the Lobry de Bruyn-van Ekenstein rearrangement to form an equilibrium mixture of D-glucose, D-mannose, and D-fructose. Therefore, D-fructose acts as a reducing sugar and gives a positive test with all three basic reagents, just like D-glucose. Thus, they cannot be used to distinguish the two sugars. Bromine water is a mild oxidizing agent that does not provide a basic medium. It oxidize