Question

Assign number 1 for least to 4 for most to indicate the relative base strength of the following.

$\stackrel{\text{I}}{{\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{N}{\text{H}}_{\text{2}}}$

$\stackrel{\text{II}}{\text{p - N}{\text{O}}_2{\text{C}}_{\text{6}}{\text{H}}_4\text{N}{\text{H}}_{\text{2}}}$

$\stackrel{\text{III}}{\text{m - N}{\text{O}}_2{\text{C}}_{\text{6}}{\text{H}}_4\text{N}{\text{H}}_{\text{2}}}$

$\stackrel{\text{IV}}{\text{m - C}{\text{H}}_3\text{O}{\text{C}}_{\text{6}}{\text{H}}_4\text{N}{\text{H}}_{\text{2}}}$

• A. I II III IV
  3 1 2 4
• B. I II III IV
  1 2 3 4
• C. I II III IV
  2 3 4 1
• D. I II III IV
  4 1 3 2

Answer 1

Answer: (A)

I II III IV

3 1 2 4

$-N{O}_2$ at para decreases more electron density making less basic(through resonance).

$-N{O}_2$ at meta has only one $-I$ effect.

$-OMe$ shows positive mesomeric effect hence increase basicity.

Hence, the correct option is $A$