NEETChemistryAmines
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Aniline reacts with nitrous acid at 273-278 K to yield a stable diazonium salt, while ethylamine yields ethanol and nitrogen gas under identical conditions. Reason (R): The stability of the benzene diazonium ion at low temperatures is due to the strong +I effect of the phenyl ring. In the light of
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A).
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A).
- C(A) is correct but (R) is not correct.
- D(A) is not correct but (R) is correct.
Correct answer
C. (A) is correct but (R) is not correct.
Step-by-step solution
Assertion (A) is correct because primary aromatic amines like aniline react with nitrous acid at 273-278 K to form arenediazonium salts which are stable at this low temperature. Primary aliphatic amines like ethylamine react under the same conditions to form highly unstable alkyl diazonium salts, which immediately decompose to yield alcohols (ethanol) and nitrogen gas. Reason (R) is incorrect because the stability of the benzene diazonium ion is due to resonance stabilization (the delocalization of the positive cha