Ncert Exercises & Solutions

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

1. (i)< (ii)< (iii)

2. (iii)< (ii)< (i)

3. (i)< (iii) <(ii)

4. (iii)< (i)< (ii)

The bond formed between C of benzene ring and halogen is more stable because of

resonance it has partial double bond character, So, rate of reaction towards

nucleophilic substitution is slow. This substitution is facilitated by the presence of

electron withdrawing group at ortho and para position because electron density is high

at these positions.

Compound (i) and (ii) both has one electron withdrawing group but in compound (i)

electron withdrawing (—NO $_{2}$ ) group is present at ortho position, so rate of reaction in

‘compound (i) is more than that of (ji) while ()) has no electron withdrawing group.

Hence, the correct option is (c).