In order to distinguigh between ` C_2H_5NH_2` and ` C_6H_5NH_2` which of the following reagenis is useful ?

Options

A. Hinsberg reagent
B. p-Naphatheol
C. Benzene diazomium chloride
D. None of the above

Explanation

To distinguish between the compounds C₂H₅NH₂ (ethanamine) and C₆H₅NH₂ (aniline), we can follow these steps:

### Step 1: Identify the Compounds
- **C₂H₅NH₂** is known as ethanamine (or ethylamine), which is a primary amine.
- **C₆H₅NH₂** is known as aniline, which is also a primary amine.

### Step 2: Choose a Suitable Reagent
Since both compounds are primary amines, we need a reagent that can differentiate between them. One effective reagent is **beta-naphthol**.

### Step 3: Perform the Diazotization Reaction
1. React aniline (C₆H₅NH₂) with sodium nitrite (NaNO₂) in the presence of hydrochloric acid (HCl) at low temperatures (0-5°C). This will convert aniline into benzene diazonium chloride (C₆H₅N₂Cl).
- Reaction:
\[ C₆H₅NH₂ + NaNO₂ + HCl \rightarrow C₆H₅N₂Cl + NaCl + 2H₂O \]

### Step 4: React with Beta-Naphthol
2. The benzene diazonium chloride formed will then be reacted with beta-naphthol. This reaction leads to the formation of an orange-red azo dye.
- Reaction:
\[ C₆H₅N₂Cl + C₁₀H₇OH \rightarrow \text{Orange-red dye} + HCl \]

### Step 5: Observe the Result
- If you observe the formation of an orange-red dye, it indicates the presence of aniline.
- If no dye is formed, it indicates the presence of ethanamine (C₂H₅NH₂), as it does not form a stable diazonium salt and therefore will not react to produce the dye.

### Conclusion
Thus, the reagent that can be used to distinguish between C₂H₅NH₂ and C₆H₅NH₂ is **beta-naphthol**.

### Final Answer
The useful reagent to distinguish between C₂H₅NH₂ and C₆H₅NH₂ is **beta-naphthol**.

---