The order of -I power (-ve inductive effect ) of the following functional groups will be:
(i) −SO3H
(ii) −Cl
(iii) −NH2
(iv) −H
I > II > III > IV
The group which withdraws electrons more will have more -I power.
→ Because of full or partial positive charge directly attached to carbon, the power of -I effect varies.
Here, in case of SO3H
Oxygen is more electronegative than S. Therefore, it will withdraw electrons from S making it positive.
Therefore,
-I effect will be more In SO3H
→ Cl is one of the most E.N. atom
→ Therefore
−SO3H > −Cl > −NH2 > −H