Question

The decreasing order of reactivity towards electrophilic substitution reaction of the following compounds is:
(i) benzene
(ii) chlorobenzene
(iii) nitrobenzene
(iv) toluene

• A. $i>iii>iv>ii$
• B. $iv>i>iii>ii$
• C. $iv>i>ii>iii$
• D. $iv>ii>i>iii$

Answer 1

Answer: (C)

$iv>i>ii>iii$

Toluene is having one methyl group which is electron-donating group causing a negative charge on the carbon atom of the ring so it is highly reactive towards electrophile which is already electron deficient.
Benzene has a delocalised set of electron cloud which attracts electrophile while chloro and nitro group are electronegative causing positive charge on carbon atom so are not reactive towards electrophilic substitution.

$Cl$ shows -I effect and $-N{O}_2$ shows strong electron-withdrawing effect. So least reactive