Fehling test is positive for

Options

A. Acetaldehyde
B. Benzaldehyde
C. Ether
D. Alcohol

Answer

**Step-by-Step Solution:**

1. **Understanding the Fehling Test**: The Fehling test is a chemical test used to detect the presence of aldehydes. It involves the use of Fehling's solution, which is an alkaline solution containing copper(II) sulfate and Rochelle salt (sodium potassium tartrate).

2. **Identifying the Types of Compounds**: The question asks which compounds give a positive result in the Fehling test. We need to differentiate between aliphatic aldehydes, aromatic aldehydes, ethers, and alcohols.

3. **Analyzing the Given Compounds**:
- **Acetaldehyde (CH3CHO)**: This is an aliphatic aldehyde. Since the Fehling test is positive for aliphatic aldehydes, this compound will give a positive result.
- **Benzaldehyde (C6H5CHO)**: This is an aromatic aldehyde. The Fehling test does not give a positive result for aromatic aldehydes, so this compound will not give a positive result.
- **Ether (ROR)**: Ethers do not contain an aldehyde group. Therefore, they will not react in the Fehling test and will not give a positive result.
- **Alcohol**: Alcohols do not contain an aldehyde group either and thus will not give a positive result in the Fehling test.

4. **Conclusion**: Based on the analysis, the only compound that gives a positive Fehling test is acetaldehyde (an aliphatic aldehyde). Therefore, the correct answer is acetaldehyde.

**Final Answer**: The Fehling test is positive for acetaldehyde.

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