Ncert Exercises & Solutions

The correct increasing order of basic strength for the following compounds is:


(I)	(II)	(III)

1. II < III < I

2. III < I < II

3. III < II < I

4. II < I < III

Hint: Electron withdrawing group decreases the basicity and electron-donating group increases the basicity of aniline

The correct increasing order of basic strength is as follows

NO₂ group withdraw the electron density from NH₂ group via -R effect.

Thus, electron density in nitrogen atom decreases and basicity of the II compound decreases.

In the case of -CH₃ group, it is a electron donating group thus,

it increases the electron density in the nitrogen atom and basicity of compound I increases.

Hence, option fourth is the correct answer.