Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Biomolecules

Question:

Glucose does not react with:

Options:

Conc. \(HNO_3\)

Acetic Anhydride

Hydroxylamine

Sodium bisulphite

Correct Answer:

Sodium bisulphite

Explanation:

The correct answer is option 4. Sodium bisulphate.

Glucose will not react with Sodium bisulphite \((NaHSO_3)\)

Glucose is a sugar molecule with an aldehyde functional group \((CHO)\). However, in its cyclic form (the most stable form), the carbonyl carbon forms a hemiacetal linkage with a hydroxyl group within the molecule.

Sodium bisulphite \((NaHSO_3)\) is a reagent commonly used to test for aldehydes and ketones. It reacts with the carbonyl group \((C=O)\) to form an addition product.

However, in glucose, the carbonyl group is involved in the hemiacetal ring formation. This restricts its free movement and hinders its reaction with \(NaHSO_3\). Additionally, steric hindrance around the hemiacetal carbon due to the surrounding hydroxyl groups in the glucose molecule further disfavors the reaction with \(NaHSO_3\).

Glucose will react with the other options:

Concentrated nitric acid \((HNO_3)\) is a strong oxidizing agent and can break down the glucose molecule.

Acetic anhydride can react with the hydroxyl groups in glucose to form ester linkages.

Hydroxylamine can react with the carbonyl group in glucose to form a ketoxime.

Therefore, the answer is (4) Sodium bisulphite \((NaHSO_3)\).