Which will not give a white ppt with ` "AgNO"_(3)`?

Options

A. Allyl chloride
B. Vinyl chloride
C. Chlorobenzene
D. Both (2) and (3)

Answer

To determine which compound will not give a white precipitate with AgNO₃, we need to analyze the reactivity of each compound with silver nitrate. The formation of a white precipitate indicates the formation of silver chloride (AgCl), which occurs when a halide (like Cl) is displaced from the alkyl halide.

### Step-by-Step Solution:

1. **Identify the Compounds**:
The compounds given are:
- Allyl fluoride
- Vinyl fluoride
- Chlorobenzene
- Both 2 and 3 (which refers to vinyl fluoride and chlorobenzene)

2. **Understanding the Reaction with AgNO₃**:
When alkyl halides react with AgNO₃, they can form silver halides (AgX), which precipitate out of solution. For Cl, this precipitate is white (AgCl).

3. **Analyzing Allyl Fluoride**:
- Allyl fluoride (C₃H₅Cl) is an alkyl halide.
- When treated with AgNO₃, it can react to form AgCl, resulting in a white precipitate.
- Therefore, allyl fluoride will give a white precipitate.

4. **Analyzing Vinyl Fluoride**:
- Vinyl fluoride (C₂H₃Cl) has a double bond adjacent to the carbon with the chlorine.
- The C-Cl bond in vinyl fluoride has partial double bond character due to resonance, which stabilizes the bond and makes it less reactive.
- Therefore, vinyl fluoride will not react with AgNO₃ to form AgCl, and thus will not give a white precipitate.

5. **Analyzing Chlorobenzene**:
- Chlorobenzene (C₆H₅Cl) is an aryl halide.
- Similar to vinyl fluoride, the C-Cl bond in chlorobenzene also exhibits partial double bond character due to resonance with the aromatic ring.
- As a result, chlorobenzene will not react with AgNO₃ to form AgCl, and thus will not give a white precipitate.

6. **Conclusion**:
- Both vinyl fluoride and chlorobenzene do not give a white precipitate with AgNO₃.
- Therefore, the correct answer is **both 2 and 3** (vinyl fluoride and chlorobenzene).

### Final Answer:
**Both 2 and 3 (vinyl fluoride and chlorobenzene) will not give a white precipitate with AgNO₃.**