Question

Arrange the following compounds in increasing order of $e^{-}$ density on benzene ring.

• A. $I>II>III>IV>V$
• B. $V>IV>III>II>I$
• C. $V>III>IV>I>II$
• D. $I>III>V>IV>II$

Answer 1

The correct option is A $I>II>III>IV>V$



$e^{-}$ density order $\propto +M,+H;$
$e^{-}$ density order $\propto \frac{1}{-M,-I}$
$\Rightarrow +M$ effect order $:-N{H}_2>-OH$
$\Rightarrow -M$ dominant over $–I$ effect, therefore $–M$ decrease the $e^{-}$ density more than $–I$
$\therefore$ Correct order of $e^{-}$ density: $I>II>III>IV>V$