Question

Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds:
Benzene (1), Toluene (2), Chlorobenzene (3) and Nitrobenzene (4)

• A. $1>2>3>4$
• B. $4>3>2>1$
• C. $2>1>3>4$
• D. $2>3>1>4$

Answer 1

The correct option is C $2>1>3>4$

We know that, electron donating group increases the electron density at ortho and para positions and thus increases the reactivity towards electrophilic substitution reactions whereas electron withdrawing group decreases the electron density at ortho and para position and thus decreases the reactivity towards electrophilic substitution.
$-C{H}_3$- Electron donating group
$-Cl$- Electron withdrawing group (-I dominates over +R effect)
$-N{O}_2$- Strongly electron withdrawing group
Hence, the correct order of reactivity is $2>1>3>4$