p-Aminoazobenzene is produced from:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Benzene diazonium chloride and aniline
A diazonium salt couples with an electron-rich aromatic ring at its para position (a coupling reaction). This is an electrophilic substitution; with aniline the product is the yellow dye p-aminoazobenzene (the book gives the equation).
Why the other options are incorrect
Option (1) Benzene diazonium chloride and phenol — Incorrect. Coupling with phenol (in alkali) gives p-hydroxyazobenzene, an orange dye, not the amino compound.
Option (3) Alkylamine and Benzene diazonium chloride — Incorrect. An alkylamine has no aromatic ring for the diazonium ion to couple with.
Option (4) Nitrobenzene and arylamine — Incorrect. Nitrobenzene has no diazonium group; it does not form an azo (–N=N–) link with an amine.
NCERT (2026-27 edition):
Reactions Involving Retention of Diazo Group
