The reaction of glucose with hydrogen cyanide confirms the .....

Options

A. straight chain structure of glucose
B. presence of a carbonyl group in glucose
C. presence of a aldehyde group in glucose
D. presence of a keto group in glucose

Answer

To solve the question regarding the reaction of glucose with hydrogen cyanide, we need to understand the chemical structure of glucose and the nature of the reaction that occurs.

### Step-by-Step Solution:

1. **Identify the Structure of Glucose**:
- Glucose is a simple sugar (monosaccharide) with the molecular formula C₆H₁₂O₆. It contains multiple hydroxyl (-OH) groups and one carbonyl (C=O) group, which is characteristic of aldehydes.

2. **Identify the Structure of Hydrogen Cyanide**:
- Hydrogen cyanide (HCN) is a simple molecule consisting of a hydrogen atom (H) and a cyanide group (CN). The cyanide ion (CN⁻) is a good nucleophile due to its electron-rich nature.

3. **Reaction Mechanism**:
- In the presence of hydrogen cyanide, the carbonyl carbon of glucose (which is an aldehyde) is electron-deficient. The nucleophilic cyanide ion attacks this carbonyl carbon, leading to the formation of a cyanohydrin.

4. **Formation of Cyanohydrin**:
- The reaction results in the addition of the cyanide ion to the carbonyl carbon, forming a new compound known as a cyanohydrin. This confirms the presence of the carbonyl group in glucose.

5. **Conclusion**:
- The reaction of glucose with hydrogen cyanide confirms the presence of a carbonyl group in glucose, which is indicative of its aldehyde functional group.

### Final Answer:
The reaction of glucose with hydrogen cyanide confirms the presence of a carbonyl group in glucose.