A colourless liquid `A(b.p. 184^(@)C)` is sparingly soluble in warm water to which it gives feebly alkaline. On treating with `NaNO_(2)` and dil `HCl` in the cold solution, it yields a solution which reacts with an alkaline solution of `beta`-naphthol to give an orange yellow precipitate. Compound A is -

Options

A. `C_(6)H_(5)N_(2)Cl`
B. `C_(6)H_(5)NHNH_(2)`
C. `n - C_4H_(9)NH_(2)`
D. `C_(6)H_(5)NH_(2)`

Answer

To solve the problem, we need to identify the compound A based on the given clues. Let's break down the information step by step.

### Step 1: Analyze the properties of compound A
- **Colorless liquid**: This indicates that compound A is likely a simple organic compound.
- **Boiling point of 184°C**: This suggests that compound A may be an aromatic amine, as many amines have higher boiling points due to hydrogen bonding.
- **Sparingly soluble in warm water and gives a feebly alkaline solution**: This is characteristic of amines, which can act as weak bases in water.

**Hint**: Consider the properties of amines and their solubility in water.

### Step 2: Reaction with NaNO2 and dilute HCl
- When compound A is treated with sodium nitrite (NaNO2) and dilute hydrochloric acid (HCl) in a cold solution, it undergoes a diazotation reaction. This indicates that compound A is likely a primary aromatic amine, which can form a diazonium salt.

**Hint**: Recall that primary aromatic amines can be converted to diazonium salts through diazotation.

### Step 3: Formation of a diazonium salt
- The reaction produces a diazonium salt, which is stable for aromatic amines but unstable for aliphatic amines. The diazonium salt will then react with beta-naphthol.

**Hint**: Identify the structure of the diazonium salt formed from an aromatic amine.

### Step 4: Reaction with beta-naphthol
- The diazonium salt reacts with an alkaline solution of beta-naphthol to give an orange-yellow precipitate. This is characteristic of azo compounds formed from the reaction of diazonium salts with phenolic compounds.

**Hint**: Azo compounds are typically formed from the coupling of diazonium salts with phenols.

### Step 5: Identify compound A
- Given the clues and the reactions, we can deduce that compound A is likely **aniline (C6H5NH2)**. Aniline is a primary aromatic amine that fits all the criteria:
- It is a colorless liquid with a boiling point around 184°C.
- It is sparingly soluble in water and gives a feebly alkaline solution.
- It can be converted to a diazonium salt and reacts with beta-naphthol to produce an orange-yellow precipitate.

**Final Answer**: Compound A is **aniline (C6H5NH2)**.