The role of concentrated `H_(2) SO_(4)` in the esterification process is :

Options

A. Catalyst
B. Dehydrating agent
C. Hydrolysing agent
D. Dehydrating agent and catalyst

Answer

To answer the question regarding the role of concentrated H₂SO₄ in the esterification process, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Esterification**:
- Esterification is a chemical reaction between a carboxylic acid and an alcohol, resulting in the formation of an ester and water. The general reaction can be represented as:
\[ \text{RCOOH} + \text{R'OH} \rightarrow \text{RCOOR'} + \text{H}_2\text{O} \]

2. **Role of Concentrated H₂SO₄**:
- Concentrated sulfuric acid (H₂SO₄) is commonly used as a catalyst in this reaction. It enhances the reaction rate without being consumed in the process.

3. **Mechanism of Action**:
- When H₂SO₄ is added to the reaction mixture, it dissociates into H⁺ ions and HSO₄⁻ ions. The H⁺ ions increase the electrophilicity of the carboxylic acid, making it more reactive towards the nucleophilic attack by the alcohol.

4. **Dehydrating Agent**:
- In addition to acting as a catalyst, concentrated H₂SO₄ also acts as a dehydrating agent. It removes water produced during the reaction, which drives the equilibrium towards the formation of more ester. This is crucial because the reaction is reversible.

5. **Final Outcome**:
- The result of using concentrated H₂SO₄ in the esterification process is the increased rate of ester formation due to its catalytic properties and the removal of water, which shifts the equilibrium towards the products.

6. **Conclusion**:
- Therefore, the role of concentrated H₂SO₄ in the esterification process is that it acts as both a dehydrating agent and a catalyst.