`C_(6) H_(5)NH_(2) underset (0-5^(@))overset(HNO_(2)//HCI)to X underset(H_(2)O)overset(Delta)to ` Phenol, Here X is :

Options

A. `phi - overset(o+)(N_(2))overset(Theta)(CI)`
B. `phi - N =C`
C. `phi - NH(CH_(3))`
D. `phi - CN`

Answer

To solve the question, we need to determine the product \( X \) formed when aniline (\( C_6H_5NH_2 \)) reacts with nitrous acid (\( HNO_2 \)) in the presence of hydrochloric acid (\( HCl \)).

### Step-by-Step Solution:

1. **Identify the Reactants:**
The reactant given is aniline, which has the chemical formula \( C_6H_5NH_2 \).

2. **Understand the Reaction Conditions:**
The reaction occurs at a low temperature (0-5°C) with nitrous acid (\( HNO_2 \)) and hydrochloric acid (\( HCl \)). This indicates a diazotization reaction.

3. **Diazotization Reaction:**
In a diazotization reaction, an amine reacts with nitrous acid to form a diazonium salt. The general reaction for aniline is:
\[ C_6H_5NH_2 + HNO_2 + HCl \rightarrow C_6H_5N_2^+Cl^- \]
Here, \( C_6H_5N_2^+Cl^- \) is benzene diazonium chloride, which is the product \( X \).

4. **Identify the Product \( X \):**
The product \( X \) formed from the reaction is benzene diazonium chloride, represented as:
\[ X = C_6H_5N_2^+Cl^- \]

5. **Further Reaction with Water:**
If benzene diazonium chloride is heated with water, it undergoes hydrolysis to form phenol:
\[ C_6H_5N_2^+Cl^- + H_2O \xrightarrow{\Delta} C_6H_5OH + N_2 + HCl \]
This confirms that \( X \) is indeed benzene diazonium chloride.

### Final Answer:
Thus, the product \( X \) is:
\[ X = C_6H_5N_2^+Cl^- \]