The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;

Step 1: Analyze the question The question asks for the name of the reaction between an organic acid (carboxylic acid) and an alcohol, with an acid catalyst (usually concentrated H₂SO₄).

Step 2: Explain the concept When a carboxylic acid reacts with an alcohol, the two combine to form an ester and water. This is called esterification. The reaction is reversible and is catalyzed by a strong acid such as concentrated sulphuric acid.

General equation:

RCOOH + R'OH ⇌ RCOOR' + H₂O (conc. H₂SO₄ catalyst)

Step 3: Solution, checking each option

• A. Saponification: This is the alkaline hydrolysis of an ester (or fat/oil) using a base like NaOH to make soap and glycerol. It is not the reaction in the question.
• B. Dehydration: This is the removal of water from a compound, for example alcohol → alkene using conc. H₂SO₄. It is not a reaction between an acid and an alcohol.
• C. Esterification: This is the reaction of a carboxylic acid with an alcohol, with an acid catalyst, giving an ester and water. ✔
• D. Hydrolysis: This is the breakdown of a compound by water. It is the reverse of esterification.

Example: CH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O (ethanoic acid + ethanol → ethyl ethanoate + water)

Step 4: Answer The correct option is C. esterification.

💡 Exam tip: Remember "Ester = Acid + Alcohol". Esters often have fruity smells, and WAEC and JAMB love asking about this. Also remember that saponification is ester + base, and hydrolysis is the reverse of esterification.