The reagents which cannot be used to distinguish benzyl chloride from chlorobenzene are

Options

A. `Br_(2)//C Cl_(4)`
B. Shaking with an aqueous solution of `AgNO_(3)`
C. Boiling with aqueous KOH solution followed by acidification with dil. `HNO_(3)` annd addition of `AgNO_(3)` solution.
D. Fusion with sodium metal followed by acidification with dil. `HNO_(3)` and addition of `AgNO_(3)` solution.

Answer

To solve the question of which reagents cannot be used to distinguish benzyl chloride from chlorobenzene, we will analyze the properties and reactions of both compounds.

### Step-by-Step Solution:

1. **Identify the Compounds**:
- **Benzyl Chloride (C6H5CH2Cl)**: This compound has a benzyl group (C6H5CH2-) attached to a chlorine atom.
- **Chlorobenzene (C6H5Cl)**: This compound has a chlorine atom directly attached to a benzene ring.

2. **Understand the Reactions**:
- **Benzyl Chloride**: It can undergo nucleophilic substitution reactions due to the presence of the benzylic carbon (the carbon attached to the chlorine). It can react with nucleophiles like NaOH to form benzyl alcohol.
- **Chlorobenzene**: It is more stable and does not undergo nucleophilic substitution easily due to the resonance stabilization of the aromatic ring. It requires harsher conditions (like the presence of a strong base) to react.

3. **Select Reagents for Distinction**:
- Common reagents that can be used to distinguish between the two include:
- **Bromine Water (Br2 in CCl4)**: This reagent can react with unsaturated compounds, leading to decolorization. Since chlorobenzene is aromatic and does not react, while benzyl chloride can react, this reagent can distinguish between them.
- **Sodium Hydroxide (NaOH)**: This can also distinguish because benzyl chloride reacts to form benzyl alcohol, while chlorobenzene does not react under normal conditions.

4. **Identify Non-Distinguishing Reagents**:
- Some reagents do not provide any distinction between benzyl chloride and chlorobenzene. For example:
- **Silver Nitrate (AgNO3)**: Both compounds can react with AgNO3 to form a white precipitate of AgCl, making it impossible to distinguish between them.
- **Alcoholic KOH**: This reagent can also lead to the formation of similar products from both compounds under certain conditions.

5. **Conclusion**:
- The reagents that cannot be used to distinguish benzyl chloride from chlorobenzene include Silver Nitrate (AgNO3) and Alcoholic KOH.

### Final Answer:
The reagents which cannot be used to distinguish benzyl chloride from chlorobenzene are **Silver Nitrate (AgNO3)** and **Alcoholic KOH**.