What happens when alkanoic acids react with alcohols in the presence of an acid catalyst?

Analysis of the Question

The question asks for the name of the chemical reaction that occurs when an alkanoic acid (carboxylic acid) reacts with an alkanol (alcohol) in the presence of an acid catalyst (usually concentrated tetraoxosulphate(VI) acid, $H_2SO_4$).

Concept Explanation

This reaction is a classic organic synthesis process known as Esterification.

In this reaction:

1. The carboxylic acid ($RCOOH$) and the alcohol ($R'OH$) undergo a condensation reaction.
2. A molecule of water ($H_2O$) is removed.
3. The resulting product is an ester ($RCOOR'$) and water.
4. The acid catalyst acts as a dehydrating agent to remove the water produced, which helps shift the equilibrium to favor the formation of the ester.

The general equation is:

Step-by-Step Solution

• Step 1: Identify the reactants. We have an alkanoic acid and an alcohol.
• Step 2: Identify the process. When these two functional groups combine with the removal of water, the product formed is an ester.
• Step 3: Evaluate the options: • A. Saponification: This is the reverse of esterification; it is the alkaline hydrolysis of an ester to produce soap and glycerol. • B. Esterification: This is the formation of an ester from an acid and an alcohol. • C. Polymerization: This is the process of joining many small monomer units to form a large polymer chain. • D. Hydrolysis: This is the breaking down of a compound by reaction with water.

Since the reaction produces an ester, the process is correctly identified as Esterification.

Conclusion

The reaction between an alkanoic acid and an alcohol to form an ester is called esterification.

Exam Tip

Remember the suffix: -ification usually implies "making." So, Esterification is the "making of an ester." Also, remember that this reaction is reversible; if you add water to an ester in the presence of an acid or base, you get the acid and alcohol back (this is called hydrolysis).