The correct option is **C. esterification**. ### Detailed Explanation: 1. **Understanding the Reaction**: - The reaction between an organic acid (which contains a carboxyl group, -COOH) and an alcohol (which contains a hydroxyl group, -OH) in the presence of an acid catalyst leads to the formation of an ester and water. This process is known as esterification. 2. **Chemical Equation**: - The general reaction can be represented as: \[ \text{RCOOH} + \text{R'OH} \xrightarrow{\text{H}^+} \text{RCOOR'} + \text{H}_2\text{O} \] - Here, RCOOH is the organic acid, R'OH is the alcohol, RCOOR' is the ester formed, and H₂O is water. 3. **Role of the Acid Catalyst**: - The acid catalyst (often sulfuric acid, H₂SO₄) helps to speed up the reaction without being consumed in the process. It protonates the carbonyl oxygen of the acid, making it more electrophilic and thus more reactive towards the alcohol. 4. **Why Other Options Are Incorrect**: - **A. Saponification**: This is a different reaction where a fat or oil (which are esters) reacts with a strong base (like NaOH) to produce glycerol and soap (salts of fatty acids). It is not related to the formation of esters from acids and alcohols. - **B. Dehydration**: This term generally refers to the removal of water from a substance. While esterification does involve the removal of water, it specifically describes the formation of esters from acids and alcohols, not just any dehydration reaction. - **D. Hydrolysis**: This is the reverse reaction of esterification. In hydrolysis, an ester reacts with water (often in the presence of an acid or base) to produce an alcohol and an organic acid. Thus, it is not the correct term for the reaction described in the question. ### Common Pitfalls: - Students often confuse esterification with hydrolysis because they are reverse reactions. Remember that esterification is the formation of an ester, while hydrolysis is the breakdown of an ester. - Misunderstanding the role of the acid catalyst can lead to confusion. It is crucial to recognize that the catalyst is not consumed in the reaction and only facilitates the process. ### Revision Summary: - **Esterification** is the reaction between an organic acid and an alcohol to form an ester and water. - An acid catalyst is used to speed up the reaction. - **Saponification** involves the reaction of fats with a base, while **hydrolysis** is the reverse of esterification. - Always remember the general formula for esterification to help with understanding and memorization.