JEE Main · 2018 · 08 Apr 2018 · Offline · Compounds Containing Nitrogen

WhatsApp Email

The increasing order of basicity of the following compounds is :
(a) (see structure)
(b) (see structure)
(c) (see structure)
(d) (see structure)

(A)(d) $<$ (b) $<$ (a) $<$ (c)
(B)(a) $<$ (b) $<$ (c) $<$ (d)
(C)(b) $<$ (a) $<$ (c) $<$ (d)
(D)(b) $<$ (a) $<$ (d) $<$ (c)✓ Correct

Answer: (D)

Solution

Basicity is governed by how available the nitrogen lone pair is and how well the protonated form is stabilised. In the vinyl amine the nitrogen is

s p^{2}

and its lone pair is partly drawn into the double bond, making it the weakest base; allylamine, with an

s p^{3}

nitrogen one carbon away from the double bond, is somewhat stronger; ethylamine is stronger still because its electron-releasing alkyl group simply pushes charge toward nitrogen; and the amidine is the strongest because protonation there is resonance-stabilised over two equivalent nitrogen-bearing forms. The increasing order of basicity runs vinyl amine, then allylamine, then ethylamine, then the amidine.

JEE Main · 2018 · 08 Apr 2018 · Offline · Single correct option

Practise more: all JEE Main PYQs on Compounds Containing Nitrogen →

JEE Main · 2018 · 08 Apr 2018 · Offline · Compounds Containing Nitrogen

Solution

More JEE Main questions on Compounds Containing Nitrogen