Which of the following reagents does not give addition reaction with acetylene?

Options

A. Acidic `KMnO_4`
B. `Cl_2`
C. Ammonical `Cu_2Cl_2`
D. None of these

Explanation

To determine which reagent does not give an addition reaction with acetylene, we will analyze each of the given reagents one by one.

### Step 1: Understanding Acetylene
Acetylene (C₂H₂) is an alkyne, which means it has a triple bond between the two carbon atoms. Alkynes typically undergo addition reactions due to the presence of this triple bond.

### Step 2: Analyzing Each Reagent
1. **Acetic Anhydride (Acetic Caminopore)**
- Acetylene reacts with acetic anhydride to form formic acid when the reaction is cold, and oxalic acid when heated. This is an addition reaction.
- **Conclusion**: Acetic anhydride does participate in an addition reaction with acetylene.

2. **Chlorine (Cl₂)**
- Acetylene reacts with chlorine to form 1,2-dichloroethane. This is also an addition reaction where chlorine adds across the triple bond of acetylene.
- **Conclusion**: Chlorine does participate in an addition reaction with acetylene.

3. **Ammonical Cu₂Cl₂**
- When acetylene reacts with ammonical Cu₂Cl₂ in the presence of NH₄OH, it does not undergo an addition reaction. Instead, it leads to a displacement reaction where hydrogen is replaced by copper.
- **Conclusion**: Ammonical Cu₂Cl₂ does not participate in an addition reaction with acetylene.

4. **Nanophase (assuming it refers to a specific form of material)**
- The behavior of nanophase materials can vary, but generally, they do not engage in addition reactions with acetylene in the same way as the other reagents. However, without specific information, we cannot definitively conclude its reactivity.

### Final Conclusion
Among the given reagents, **Ammonical Cu₂Cl₂** is the one that does not give an addition reaction with acetylene.

### Summary of Steps:
1. Identify the nature of acetylene as an alkyne.
2. Analyze each reagent for its reaction with acetylene.
3. Conclude which reagent does not participate in an addition reaction.