Arrange the following compounds in order of their decreasing reactivity with an electrophile,`E^((+)`
i) Chlorobenzene
ii) 2,4- dinitrochlorobenzene
iii)` p`- nitrochlorobenzene

Options

A. (iii) gt (ii) gt (i)
B. (ii) gt (iii) gt (i)
C. (i) gt (iii) gt (ii)
D. (i) gt (ii) gt (iii)

Answer

C

Explanation

In (i), one deactivating group (–Cl) is present. In (ii), 3 deactivating groups (2–`NO_(2)` and 1 –Cl) are present, and in (iii), 2 deactivating groups (`–NO_(2)` and –Cl) are present.
So order is `(i) gt (iii) gt (ii)`.