Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+ (a)Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene (b) Toluene, p-H_3C–C_6H_4–NO_(2), p-O_2N–C_6H_4–NO_2.

Arrange the following set of compounds in order of their decreasing re

1.	Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+ (a)Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene (b) Toluene, p-H_3C–C_6H_4–NO_(2), p-O_2N–C_6H_4–NO_2.
Answer» Solution : Since-`NO_2`is a more powerful electron-withdrawing group than - CI, it deactivates the ring to a GREATER extent. HIGHER the number of `-NO_2`groups, greater is the deactivating effect. Hence, the decreasing order of reactivity of the given compounds FOLLOWS the following order : Chlorobenzene > p-nitrochlorobenzene > 2, 4-dinitrochlorobenzene