Organic chemistry — understanding esterification Which statement correctly characterizes an esterification reaction in organic chemistry?

Introduction / Context:
Esterification is a fundamental transformation in organic chemistry used to form esters, which appear in flavors, fragrances, solvents, and polymers. Understanding what esterification is (and is not) avoids confusion with related reactions like saponification.

Given Data / Assumptions:

• Classical Fischer esterification involves an alcohol and a carboxylic acid with an acid catalyst.
• Water is formed as a by-product, and the reaction is reversible.

Concept / Approach:
In Fischer esterification, the key equilibrium is: alcohol + carboxylic acid ⇌ ester + water (acid-catalyzed). Driving the equilibrium (e.g., removing water) increases ester yield. Soapmaking (saponification) is a different reaction: base-catalyzed hydrolysis of esters (fats) to yield glycerol and soaps.

Step-by-Step Solution:
Identify reactants: alcohol + carboxylic acid.Identify products: ester + water.Note reversibility: equilibrium reaction sensitive to water removal or excess reactant.Select the option that captures these features → option (b).

Verification / Alternative check:
Standard texts describe Fischer esterification as reversible; Le Châtelier’s principle applies via water removal or reactant excess.

Why Other Options Are Wrong:

• Option (a): describes saponification/soap formation, not esterification.
• Option (c): incorrect on both irreversibility and reactants.
• Option (d): polymerization of ethene forms polyethylene, not polyesters; polyesters come from diols + diacids/derivatives or ring-opening of lactones.

Common Pitfalls:

• Confusing esterification with soapmaking (reverse direction under basic conditions).

Final Answer:
It is reversible and occurs between an alcohol and a carboxylic acid