Sulphonation of phenol with conc. `H_(2)SO_(4)` at 288-298 K gives

Options

A. p-Phenolsulphonic acid
B. Sulphanilic acid
C. o-Phenolsulphonic acid
D. m-Phenolsulphonic acid

Answer

To solve the question regarding the sulfonation of phenol with concentrated H₂SO₄ at a temperature of 288-298 K, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Reactants**:
- We start with phenol (C₆H₅OH) and concentrated sulfuric acid (H₂SO₄). Phenol has a hydroxyl (-OH) group attached to a benzene ring.

2. **Reaction Conditions**:
- The reaction is carried out at a temperature range of 288-298 K. The temperature is crucial as it influences the position where the sulfonic acid group (SO₃H) will attach to the benzene ring.

3. **Mechanism of Sulfonation**:
- Sulfonation involves the electrophilic substitution of the hydrogen atom on the benzene ring with the sulfonic acid group (SO₃H).
- The -OH group on phenol is a strong activating group and directs electrophilic substitution primarily to the ortho and para positions relative to itself.

4. **Position of Substitution**:
- At lower temperatures, the reaction tends to favor the para position due to steric hindrance at the ortho position.
- However, at the specified temperature range of 288-298 K, the reaction favors the ortho position due to the increased reactivity of phenol and the conditions of the reaction.

5. **Product Formation**:
- Therefore, the product formed when phenol reacts with concentrated H₂SO₄ at 288-298 K is ortho-phenol sulfonic acid, where the SO₃H group is attached to the ortho position of the benzene ring.

6. **Conclusion**:
- Based on the above reasoning, the correct answer to the question is ortho-phenol sulfonic acid.

### Final Answer:
The sulfonation of phenol with concentrated H₂SO₄ at 288-298 K gives **ortho-phenol sulfonic acid**.