What is the correct order of the acidic strength of primary (1°), secondary (2°) and tertiary (3°) alcohols?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 1° > 2° > 3°
The acidity of an alcohol comes from the polar O–H bond. Each alkyl group is electron-releasing and makes this bond less polar, so the more alkyl groups on the carbon carrying –OH, the weaker the acid.
Primary alcohol, \( \ce{RCH2OH} \) — first: only one alkyl group on the carbon carrying –OH, so the O–H bond stays most polar.
Secondary alcohol, \( \ce{R2CHOH} \) — second: two alkyl groups release more electron density to the oxygen.
Tertiary alcohol, \( \ce{R3COH} \) — last: three alkyl groups give the least polar O–H bond and the weakest acid.
NCERT (2026-27 edition):
7.4.4 Chemical Reactions
