Due to resonance,the oxygen atom of the $-OH$ group in phenol:

The heating of phenyl methyl ether with $HI$ produces an aromatic compound $A$ which on treatment with conc. $HNO_3$ gives $B$. $A$ and $B$ respectively are

$4$-Hydroxybenzenesulphonic acid is treated with bromine water. The product formed is -

Phenol on oxidation in air gives

Sodium bicarbonate reacts with salicylic acid to form:

The major product of the following reaction is: