Carboxylic acid forms ester on reaction with alcohol in presence of mineral acid. Esterification reaction is a kind of
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Nucleophilic acyl substitution
In esterification, a carboxylic acid is heated with an alcohol in the presence of a mineral acid such as conc. \( \ce{H2SO4} \) or HCl gas:
\( \displaystyle \ce{RCOOH + R'OH} \xrightarrow{\ce{H^+}} \ce{RCOOR' + H2O} \)
The net result is that the –OH group on the acyl carbon is replaced by –OR′ while the acyl group (RCO–) stays intact. So esterification is a nucleophilic acyl substitution.
Why the other options are incorrect
Option (2) Nucleophilic addition — Incorrect. This is typical of aldehydes and ketones, which have no leaving group; the product keeps all groups (e.g. cyanohydrins). In esterification the addition step is followed by loss of water.
Option (3) Electrophilic substitution — Incorrect. This is typical of aromatic rings, where an electrophile replaces a ring hydrogen.
Option (4) Electrophilic addition — Incorrect. This is typical of alkenes and alkynes, which add HX or \( \ce{X2} \) across the multiple bond.
NCERT (2026-27 edition):
Mechanism of Esterification of Carboxylic Acids
