Which of the following compound gives dye test ?

Options

A. Aniline
B. Methylamine
C. Diphenylamine
D. Ethylamine

Answer

To determine which compound gives the dye test, we need to analyze the options provided: aniline, methyl amine, diphenyl amine, and ethyl amine. The dye test is used to distinguish between aromatic primary amines and aliphatic primary amines.

### Step-by-Step Solution:

1. **Understanding the Dye Test**:
- The dye test is specifically used to identify aromatic primary amines. Aromatic primary amines will react with nitrous acid (HNO2) to form diazonium salts, which can then react with beta-naphthol to produce a colored dye.

2. **Identifying the Compounds**:
- **Aniline (C6H5NH2)**: This is an aromatic primary amine.
- **Methyl Amine (CH3NH2)**: This is an aliphatic primary amine.
- **Diphenyl Amine (C6H5)2NH**: This is a secondary aromatic amine.
- **Ethyl Amine (C2H5NH2)**: This is also an aliphatic primary amine.

3. **Analyzing Each Compound**:
- **Aniline**: As an aromatic primary amine, it will give a positive dye test. When treated with HNO2, it forms benzene diazonium chloride, which can react with beta-naphthol to produce an orange or red dye.
- **Methyl Amine**: Being an aliphatic primary amine, it does not give the dye test.
- **Diphenyl Amine**: This is a secondary amine and will not give the dye test.
- **Ethyl Amine**: Similar to methyl amine, it is an aliphatic primary amine and does not give the dye test.

4. **Conclusion**:
- The only compound that gives the dye test is **aniline**.

### Final Answer:
The compound that gives the dye test is **aniline**.

---