STATEMENT-1: Aniline on reaction with at 0 °C followed by coupling with β-naphthol gives a dark blue coloured precipitate.
and
STATEMENT-2: The colour of the compound formed in the reaction of aniline with at 0 °C followed by coupling with β-naphthol is due to the extended conjugation.
and
STATEMENT-2: The colour of the compound formed in the reaction of aniline with at 0 °C followed by coupling with β-naphthol is due to the extended conjugation.
- (A)STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1
- (B)STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1
- (C)STATEMENT-1 is True, STATEMENT-2 is False
- (D)STATEMENT-1 is False, STATEMENT-2 is True✓ Correct
Answer: (D)
Solution
STATEMENT-1 is false because aniline reacts with at 0 °C to form benzenediazonium chloride, which upon coupling with β-naphthol gives a scarlet red (orange-red) colored azo dye, not dark blue.
STATEMENT-2 is true because azo dyes are indeed colored due to extended conjugation in the molecule, which allows for absorption of visible light through π→π* transitions.
STATEMENT-2 is true because azo dyes are indeed colored due to extended conjugation in the molecule, which allows for absorption of visible light through π→π* transitions.
JEE Advanced · 2008 · 13 Apr 2008 · Paper 2 · Single correct option