Question

Replacement of Cl of chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-dinitrochlorobenzene is readily replaced. This is because 

(a) NO₂ makes the ring electron rich at ortho and para positions 

(b) NO₂ withdraws e^- from meta position 

(c) NO₂ donates e^- at meta position 

(d) NO₂ withdraws e^- from ortho/para positions

Answer 1

(d) NO₂ withdraws e^- from ortho/para positions

NO₂ group shows −M effect due to which electrons are withdrawn from ortho and para position which makes the benzene ring more prone to electrophilic substitution reaction and hence replacement of Cl can be done easily.