JEE Main · 2019 · 08 Apr 2019 · Shift 1 · Compounds Containing Nitrogen

In the following compounds, the decreasing order of basic strength will be:

(A) $C_{2} H_{5} NH_{2} > NH_{3} > (C_{2} H_{5})_{2} NH$
(B) $NH_{3} > C_{2} H_{5} NH_{2} > (C_{2} H_{5})_{2} NH$
(C) $(C_{2} H_{5})_{2} NH > C_{2} H_{5} NH_{2} > NH_{3}$ ✓ Correct
(D) $(C_{2} H_{5})_{2} NH > NH_{3} > C_{2} H_{5} NH_{2}$

Answer: (C)

Solution

For these amines in solution the basicity reflects the electron density pushed onto nitrogen by the alkyl groups through their

+ I

effect, tempered by solvation of the protonated form. Adding ethyl groups raises that electron density, so diethylamine is more basic than ethylamine, which is in turn more basic than ammonia. The decreasing order of basic strength is

(C_{2} H_{5})_{2} NH > C_{2} H_{5} N H_{2} > N H_{3}

JEE Main · 2019 · 08 Apr 2019 · Shift 1 · Single correct option

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JEE Main · 2019 · 08 Apr 2019 · Shift 1 · Compounds Containing Nitrogen

Solution

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