Which of the following does not give effervescence with `NaHCO_(3)` ?

Options

A. Phenol
B. p-Nitrophenol
C. 2,4-dinitrophenol
D. 2,4,6-trinitrophenol

Explanation

To determine which of the following compounds does not give effervescence with sodium bicarbonate (NaHCO₃), we need to analyze the acidic properties of each compound listed. Sodium bicarbonate is a weak base and will react with strong acids to produce carbon dioxide (CO₂) gas, which is what causes effervescence.

### Step-by-Step Solution:

1. **Identify the Compounds**:
The compounds given are:
- A) Phenol
- B) Para-nitrophenol
- C) 2,4-Dinitrophenol
- D) 2,4,6-Trinitrophenol

2. **Understand the Nature of Sodium Bicarbonate**:
Sodium bicarbonate (NaHCO₃) is a weak base. It will react with strong acids to release CO₂ gas, which results in effervescence.

3. **Determine the Acidity of Each Compound**:
- **Phenol**: A weak acid.
- **Para-nitrophenol**: Has a nitro group that is electron-withdrawing, making it a stronger acid than phenol.
- **2,4-Dinitrophenol**: Contains two nitro groups, further increasing its acidity.
- **2,4,6-Trinitrophenol**: Contains three nitro groups, making it a very strong acid.

4. **Analyze the Reactivity with NaHCO₃**:
- Since NaHCO₃ is a weak base, it will not react with weak acids.
- Among the compounds, phenol is the weakest acid, while the others (para-nitrophenol, 2,4-dinitrophenol, and 2,4,6-trinitrophenol) are stronger acids due to the presence of electron-withdrawing nitro groups.

5. **Conclusion**:
- Since phenol is a weak acid, it will not react with sodium bicarbonate to produce effervescence. Therefore, the answer to the question is **A) Phenol**.

### Final Answer:
**Phenol (Option A) does not give effervescence with NaHCO₃.**