Question

Arrange the following compounds in increasing dipole moment.
toluene $\left(I\right)$, $m$-chlorobenzene $\left(II\right)$, $o$-dichlorobenzene $\left(III\right)$, $p$-dichlorobenzene $\left(IV\right)$

• A. $I<IV<II<III$
• B. $IV<I<II<III$
• C. $IV<I<III<II$
• D. $IV<II<I<III$

Answer 1

The correct option is B $IV<I<II<III$

Due to symmetrical structure, p-dichlorobenzene have zero dipole moment.
Also, in toluene methyl group have $+I$ effect while $Cl$ have $-I$ effect so toluene have low dipole moment.