Question

Arrange the following functional groups in the order of decreasing -I power (-ve inductive effect ):

• A. $-S{O}_{3}H$
• B. $-Cl$
• C. $-H$
• D. $-N{H}_2$

Answer 1

The group which withdraws electrons more will have more -I power.
$\to$ Because of full or partial positive charge directly attached to carbon, the power of -I effect varies.
Here, in case of $-S{O}_{3}H$
oxygen is more electronegative than $S$. Therefore, it will withdraw electrons from $S$ making it positive.Therefore,
-I effect will be more In $-S{O}_{3}H$
$\to$ $Cl$ is one of the most E.N. atom
Therefore, the order of -I effect is:

$-S{O}_{3}H>-Cl>-N{H}_2>-H$