Question

Glucose fails to react with:

• A. Phenyl hydrazine
• B. NaHSO${}_3$
• C. Tollens reagent
• D. Fehling solution

Answer 1

The correct option is B NaHSO${}_3$

Glucose contains an alcoholic group and an aldehyde group. So the test which are given by an alcohol and an aldehyde are given positively by Glucose. Hence, glucose will give the positive test for Phenyl hydrazine, Tollens reagent and Fehling solution, which are given by an aldehyde. Since $NaHS{O}_3$ is a basic salt, it will not react with glucose, as it does not contain an acid.