Arrange the following set of compounds in the order of their decreasing relative reactivity with an electrophile . Give reason.

Explanation

The methoxy group` (-OCH_(3)`) is electon releasing group. It increases the electron density in benzene nucleus due to resonance effect (+R-effect). It makes anisole more reactive than benzene towards electrophile.

In case of alkyl halides , halogens are moderately deactivating because of their strong -I effect. Thus, overall electron density on benzene ring decreases. It makes further substitution difficult.
`-NO_(2)` group is electron withdrawing group. It decreases the electron density in benzene nucleus due to its strong - R- effect and strong -I-effect. Hence, it makes nitrobenzene less reactive. Therefore , overall rearll reactivity of these three compounds towards electrophiles decreases in the following order