JEE MainChemistryBiomolecules
The incorrect statement regarding the chemical reactions of glucose is :
Options
- AOn prolonged heating with HI, glucose forms n-hexane
- BGlucose forms an addition product with NaHSO₃
- CGlucose reacts with acetic anhydride to form glucose pentaacetate
- DOn reaction with bromine water, glucose gets oxidized to gluconic acid
Correct answer
B. Glucose forms an addition product with NaHSO₃
Step-by-step solution
Despite having an aldehyde group, glucose does not form an addition product with NaHSO₃ (or 2,4-DNP reagent). This is because the aldehyde group is not free; it is involved in hemiacetal formation, existing primarily in a cyclic structure. Prolonged heating with HI gives n-hexane, confirming the straight chain of 6 carbon atoms. Acetylation with acetic anhydride gives glucose pentaacetate, confirming the presence of five -OH groups. Bromine water is a mild oxidizing agent that oxidizes the aldehyde group to a carbo