Aliphatic aldehyde can be oxidised by

Options

A. Tollen's reagent
B. Fehling solution
C. Benedict solution
D. All of these

Answer

To answer the question "Aliphatic aldehyde can be oxidised by," we will analyze the options provided and determine which reagents can oxidize aliphatic aldehydes.

### Step-by-Step Solution:

1. **Understanding Aliphatic Aldehydes**:
- Aliphatic aldehydes are organic compounds containing the functional group -CHO, where the carbon atom is part of an open chain (not a ring).

2. **Identifying Oxidizing Agents**:
- We need to identify which reagents can oxidize these aldehydes. Common oxidizing agents for aldehydes include Tollens' reagent, Fehling's solution, and Benedict's solution.

3. **Tollens' Reagent**:
- Tollens' reagent is a solution of silver nitrate (AgNO3) in ammonia (NH3). It is known to oxidize both aliphatic and aromatic aldehydes.
- **Conclusion**: Tollens' reagent can oxidize aliphatic aldehydes.

4. **Fehling's Solution**:
- Fehling's solution is an alkaline solution containing copper(II) sulfate and Rochelle salt (sodium potassium tartrate). It specifically oxidizes aldehydes, particularly aliphatic aldehydes, but does not oxidize aromatic aldehydes.
- **Conclusion**: Fehling's solution can oxidize aliphatic aldehydes.

5. **Benedict's Solution**:
- Benedict's solution is similar to Fehling's solution and contains sodium carbonate, sodium citrate, and copper(II) sulfate. It is used as a test for reducing sugars and can also oxidize aliphatic aldehydes.
- **Conclusion**: Benedict's solution can oxidize aliphatic aldehydes.

6. **Final Conclusion**:
- Since all three reagents (Tollens' reagent, Fehling's solution, and Benedict's solution) can oxidize aliphatic aldehydes, the correct answer to the question is "all of these."

### Final Answer:
Aliphatic aldehyde can be oxidized by **Tollens' reagent, Fehling's solution, and Benedict's solution**. Therefore, the answer is **all of these**.

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