Arrange the compounds in increasing order of rate of reaction towards nucleophilic substitution reaction:

   (i)        (ii)       (iii)

1. (i) < (ii) < (iii)       

2. (i) < (iii) < (ii) 

3. (iii) < (ii) < (i) 

4. (ii) < (iii) < (i) 

Hint: Electron donating group at ortho and para position decreases the rate of nucleophilic substitution reaction

The presence of electron releasing group at ortho or para position decreases the rate of

nucleophilic substitution reaction, In compound (ii), the electron releasing group is present at meta position w.r.t chlorine, so the impact is less but in compound (i) it is present at the ortho position.

Thus, the rate of reaction towards nucleophilic substitution is least in compound (ii) and

highest in compound (i) as there is no electron releasing group in this compound.