Which of the following is a trihydric phenol ?

Options

A. Resorcinol
B. p - cresol
C. phloroglucinol
D. Catechol

Answer

To determine which of the given compounds is a trihydric phenol, we need to identify the structure of each compound and count the number of hydroxyl (–OH) groups attached to the phenolic ring. A trihydric phenol will have three –OH groups.

### Step-by-Step Solution:

1. **Understand the Definition**: A trihydric phenol is a phenolic compound that contains three hydroxyl (–OH) groups attached to the benzene ring.

2. **Analyze the Given Options**: We will evaluate each option to see how many –OH groups are present.

3. **Option A: Resorcinol**
- Structure: Resorcinol has two –OH groups at the 1 and 3 positions of the benzene ring.
- Conclusion: Resorcinol is a dihydric phenol (two –OH groups), not trihydric.

4. **Option B: Para-cresol (4-methylphenol)**
- Structure: Para-cresol has one –OH group at the para position and a methyl group at the 4 position.
- Conclusion: Para-cresol is also a dihydric phenol (one –OH group), not trihydric.

5. **Option C: Phloroglucinol**
- Structure: Phloroglucinol has three –OH groups at the 1, 2, and 3 positions of the benzene ring.
- Conclusion: Phloroglucinol is a trihydric phenol (three –OH groups).

6. **Option D: Catechol**
- Structure: Catechol has two –OH groups at the 1 and 2 positions of the benzene ring.
- Conclusion: Catechol is a dihydric phenol (two –OH groups), not trihydric.

7. **Final Answer**: Based on the analysis, the compound that is a trihydric phenol is **Option C: Phloroglucinol**.