MolSynapsequestion bank
MolSynapse / Question bank / Amines and Aromatic Nitrogen Compounds / Diazonium salts: preparation and synthetic uses
JEE Advanced levelSingle correct optionDifficulty 3 of 3nc142

Assertion: Coupling of benzenediazonium chloride with aniline to give 4-aminoazobenzene is carried out in a mildly acidic medium (pH 4-5) and not in strongly acidic solution. Reason: In strongly acidic solution the amine is converted into the anilinium ion, which is deactivated towards attack by the weakly electrophilic diazonium ion.

  1. ABoth Assertion and Reason are true and the Reason is the correct explanation of the Assertion
  2. BBoth Assertion and Reason are true but the Reason is not the correct explanation of the Assertion
  3. CAssertion is true but Reason is false
  4. DAssertion is false but Reason is true

Answer: A

The diazonium ion is a weak electrophile and needs a strongly activated ring. In strong acid aniline is protonated to , whose positively charged group deactivates the ring, so coupling fails; at pH 4-5 enough free amine remains. The Reason correctly explains the Assertion.
Practice Amines and Aromatic Nitrogen Compounds More on Diazonium salts: preparation and synthetic uses
Previous questionNext question

More questions on Diazonium salts: preparation and synthetic uses