Acetylene does not react with

Options

A. Na
B. ammoniacal `AgNO_3`
C. HCl
D. NaOH

Answer

To determine which substance acetylene does not react with, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Identify the Structure of Acetylene**:
- Acetylene is also known as ethyne and has the chemical formula C₂H₂. It is an alkyne with a triple bond between the two carbon atoms.

2. **Evaluate Reaction with Sodium (Na)**:
- When acetylene (C₂H₂) reacts with sodium (Na), it forms a sodium acetylide (C≡C⁻Na⁺) by removing one of the acidic hydrogens.
- **Conclusion**: Reaction occurs with sodium.

3. **Evaluate Reaction with Ammoniacal AgNO₃**:
- Ammoniacal AgNO₃ (Tollens' reagent) reacts with terminal alkynes to form a silver acetylide complex.
- **Conclusion**: Reaction occurs with ammoniacal AgNO₃.

4. **Evaluate Reaction with Hydrochloric Acid (HCl)**:
- Acetylene reacts with HCl through an addition reaction, resulting in the formation of vinyl chloride (C₂H₃Cl) and further addition can lead to dichloroethane (C₂H₄Cl₂).
- **Conclusion**: Reaction occurs with HCl.

5. **Evaluate Reaction with Sodium Hydroxide (NaOH)**:
- When acetylene reacts with NaOH in aqueous solution, the acidic hydrogen is removed to form sodium acetylide. However, this salt can be protonated back to regenerate acetylene in the presence of water.
- **Conclusion**: No net reaction occurs with NaOH as acetylene is regenerated.

### Final Answer:
Acetylene does not react with **Sodium Hydroxide (NaOH)**.

---