Question

Glucose does not give 2 4 DNP test and schiff's test.why?

Answer 1

This is because glucose does not react with Schiff's reagent & 2,4DNP reagent although it has an aldehydic group.After the internal cyclisation,it forms either α-anomer.In these forms free aldehydic group is not present.So,it does not give a reaction of aldehydic group.