Which of the following reacts with ammonical cuprous chloride?

Options

A. `CH_(4)`
B. `C_(2)H_(2)`
C. `C_(2)H_(6)`
D. `C_(6)H_(6)`

Answer

To determine which of the following compounds reacts with ammonical cuprous chloride, we will analyze the options provided: CH4 (methane), C2H2 (acetylene), C2H6 (ethane), and C6H6 (benzene).

### Step-by-Step Solution:

1. **Understanding Ammonical Cuprous Chloride**:
- Ammonical cuprous chloride is a reagent that consists of cuprous chloride (CuCl) dissolved in an ammonia solution. It is known to react with certain types of hydrocarbons, particularly alkynes.

2. **Analyzing the Options**:
- **CH4 (Methane)**: Methane is an alkane and does not have any multiple bonds (double or triple bonds). It is generally unreactive towards ammonical cuprous chloride.
- **C2H2 (Acetylene)**: Acetylene is an alkyne with a triple bond between the two carbon atoms. Alkynes are known to react with ammonical cuprous chloride, forming a copper acetylide precipitate.
- **C2H6 (Ethane)**: Ethane is also an alkane and, similar to methane, does not have any multiple bonds. It does not react with ammonical cuprous chloride.
- **C6H6 (Benzene)**: Benzene is an aromatic compound and does not react with ammonical cuprous chloride either.

3. **Conclusion**:
- Among the given options, only **C2H2 (acetylene)** reacts with ammonical cuprous chloride to form a red precipitate of copper acetylide.

### Final Answer:
The compound that reacts with ammonical cuprous chloride is **C2H2 (acetylene)**.