Which of the following test can be used for identification of
`1^(@)` amine ?

Options

A. Carbylamine test
B. Hofmann mustard oil reaction
C. `NaNO_(2)//HCl`
D. Fehling's solution

Explanation

To identify primary amines, we can use the following tests:

1. **Carbylamine Test**:
- **Procedure**: Mix the primary amine (RNH2) with chloroform (CHCl3) and alcoholic potassium hydroxide (KOH). Heat the mixture.
- **Observation**: The formation of an alkyl isocyanide indicates a positive result. This test is specific for primary amines and does not react with secondary or tertiary amines.

2. **Hofmann Mustard Oil Reaction**:
- **Procedure**: React the primary amine (RNH2) with carbon disulfide (CS2) and mercuric chloride (HgCl2).
- **Observation**: The formation of alkyl isothiocyanate is a positive result. This reaction is also specific for primary amines.

3. **Diazotization Test**:
- **Procedure**: Treat the primary amine with sodium nitrite (NaNO2) in hydrochloric acid (HCl).
- **Observation**: For aromatic primary amines, this forms diazonium salts. For aliphatic primary amines, it leads to the formation of alcohol, nitrogen gas, and water. This test is also specific for primary amines.

4. **Fehling's Solution Test**:
- **Observation**: This test is not applicable for primary amines as it is used for the identification of reducing sugars and aldehydes.

### Conclusion:
The tests that can be used for the identification of primary amines are:
- Carbylamine Test
- Hofmann Mustard Oil Reaction
- Diazotization Test

**Final Answer**: The correct tests for identifying primary amines are 1, 2, and 3.

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