Question

Glucose and fructose can be differentiated by:

• A. Tollen's reagent
• B. Barfoed’s test
• C. Seliwanoff’s test
• D. Molisch test

Answer 1

The correct option is C Seliwanoff’s test

Tollen's test is give by aldehydes and $\alpha$-hydroxy ketones. Therefore, glucose and fructose both give positive Tollen's test. Hence, it cannot be used to differentiate between the two.

Barfoed's test is given by reducing monosaccharides. Since glucose and fructose both are reducing monosaccharides hence they both will give positive Barfoed's test. Hence, it cannot be used to differentiate between the two.

Seliwanoff's test is used to distinguish between aldose and ketose sugars. Hence, glucose and fructose can de differentiated by Seliwanoff's test.

Molisch test is give by all the carbohydrates. Hence, glucose and fructose cannot de differentiated by Molisch test.