Presence of carbonyl group in glucose can be shown by its reaction with

Options

A. `NH_2 OH`
B. `HCN`
C. Tollen's reagent
D. All of these

Answer

To determine the presence of a carbonyl group in glucose, we can perform a series of reactions with specific reagents. Here’s a step-by-step solution:

### Step 1: Understanding the Structure of Glucose
Glucose is a monosaccharide with the molecular formula C6H12O6. It contains a carbonyl group (C=O) in the form of an aldehyde at one end of the molecule.

### Step 2: Reaction with Hydroxylamine (NH2OH)
1. **Add Hydroxylamine (NH2OH)**: When glucose reacts with hydroxylamine, it forms an oxime. This reaction indicates the presence of a carbonyl group because hydroxylamine reacts specifically with aldehydes and ketones.
2. **Formation of Hydroxylamine Derivative**: The reaction leads to the release of water (H2O) and the formation of a compound known as an oxime.

### Step 3: Reaction with Hydrogen Cyanide (HCN)
1. **Add Hydrogen Cyanide (HCN)**: The carbonyl group in glucose can also react with HCN. This reaction results in the formation of a cyanohydrin.
2. **Nucleophilic Addition**: The cyanide ion (CN-) acts as a nucleophile and adds to the carbonyl carbon, demonstrating the presence of the carbonyl group through nucleophilic addition.

### Step 4: Reaction with Tollen's Reagent
1. **Add Tollen's Reagent**: Tollen's reagent is a solution of silver nitrate in ammonia (Ag(NH3)2+). When glucose is treated with Tollen's reagent, the aldehyde group gets oxidized to a carboxylic acid.
2. **Formation of Silver Precipitate**: This reaction produces a silver precipitate (black precipitate of silver) and confirms the presence of the carbonyl group, as Tollen’s reagent specifically reacts with aldehydes.

### Conclusion
Through these reactions with hydroxylamine, hydrogen cyanide, and Tollen's reagent, we can confirm the presence of the carbonyl group in glucose.

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