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Amines · Question 36

JEE Main 2025 (Online) 2nd April Morning ShiftMCQMedium📈 Topic in 10% papers+4−1
1

The correct order of basic nature in aqueous solution for the bases NH3, H2N-NH2, CH3CH2NH2, (CH3CH2)2NH and (CH3CH2)3N is :

  1. NH3 < H2N-NH2 < (CH3CH2)3N < CH3CH2NH2 < (CH3CH2)2NH
  2. H2N-NH2 < NH3 < (CH3CH2)3N < CH3CH2NH2 < (CH3CH2)2NH
  3. H2N-NH2 < NH3 < CH3CH2NH2 < (CH3CH2)3N < (CH3CH2)2NH
  4. NH3 < H2N-NH2 < CH3CH2NH2 < (CH3CH2)2NH < (CH3CH2)3N

Answer

(3) H2N-NH2 < NH3 < CH3CH2NH2 < (CH3CH2)3N < (CH3CH2)2NH

Solution

Hydrazine: the –I effect of the neighbouring -NH2 group lowers the electron density on N weaker base than NH3 (pKb 5.9 vs 4.75).

Ethylamines are stronger bases than NH3 because of the +I effect of ethyl groups.

In aqueous solution, +I effect, H-bonding (solvation) of the cation and steric hindrance together decide the order. As per NCERT, for ethyl groups: (C2H5)2NH > (C2H5)3N > C2H5NH2 > NH3

(pKb: 3.00, 3.25, 3.29, 4.75)

H2N-NH2 < NH3 < CH3CH2NH2 < (CH3CH2)3N < (CH3CH2)2NH

Answer: (3)

JEE Main 2025 (Online) 2nd April Morning Shift

Keep practising — Amines

2

When a concentrated solution of sulphanilic acid and 1-naphthylamine is treated with nitrous acid (273 K) and acidified with acetic acid, the mass (g) of 0.1 mole of product formed is: (Given molar mass in g mol-1 H : 1, C : 12, N : 14, O : 16, S : 32)

  1. 330
  2. 33
  3. 343
  4. 66
JEE Main 2025 (Online) 2nd April Evening Shift
3

Given below are some nitrogen containing compounds : [figure] Each of them is treated with HCl separately. 1.0 g of the most basic compound will consume mg of HCl. (Given molar mass in g mol-1 C : 12, H : 1, O : 16, Cl : 35.5)

JEE Main 2025 (Online) 29th January Morning Shift
4

Consider the following sequence of reactions: [figure] 11.25 mg of chlorobenzene will produce 10-1 mg of product B. (Consider the reactions result in complete conversion.) [Given molar mass of C, H, O, N and Cl as 12, 1, 16, 14 and 35.5 g mol-1 respectively]

JEE Main 2025 (Online) 28th January Morning Shift
5

Identify correct statements : Choose the correct answer from the options given below :

  1. (B) and (C) only
  2. (D) and (E) only
  3. (A) and (B) only
  4. (B) and (D) only
JEE Main 2025 (Online) 28th January Evening Shift

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