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Read the passage given below and answer the following questions:
Although chlorobenzene is inert to nucleophilic substitution, however it gives quantitative yield of phenol when heated with aq. $Na OH$ at high temperature and under high pressure. As far as electrophilic substitution in phenol is concemed the — OH group is an activating group, hence, its presence enhances the electrophilic substitution at o - and p - positions.
The following questions are multiple choice questions. Choose the most appropriate answer:

1. Conversion of chlorobenzene into phenol involves:

1. Modified $S_N1$ mechanism.
2. Modified $S_N2$ mechanism.
3. Both (a) and (b).
4. Elimination-addition mechanism.

2. Phenol undergoes electrophilic substitution more readily than benzene because:

1. The intermediate carbocation is a resonance hybrid of more resonating structures than that from benzene.
2. The intermediate is more stable as it has positive charge on oxygen, which can be better accommodated than on carbon.
3. In one of the canonical structures, every atom (except hydrogen) has complete octet.
4. The — OH group is o, p-directing which like all other o, p - directing group, is activating.

3. Phenol on treatment with excess of cone. $HNO_3$ gives:

1. O - nitrophenol.
2. P - nitrophenol.
3. O - and p - nitrophenol.
4. 2, 4, 6 - trinitrophenol.

4. Phenol is heated with a solution of mixture of $KBr$ and $KBrO_3$. The major product obtained in the above reaction is:

1. 2 - bromophenol.
2. 3 - bromophenol.
3. 4 - bromophenol.
4. 2, 4, 6 - tribromophenol.

5. The major product of the following reaction is: