Which one of the following compounds will readily react with dilute $NaOH$?

Phenol $+$ Aniline $\xrightarrow[{KOH}]{{C_6H_5N_2^+Cl^{-}}}$ Major Product $:$ Product will be $:$

The ionisation constant of phenol is higher than that of ethanol because

Identify the product obtained when phenol is heated with $Zn$ dust.

The number of $\sigma$ bonds in carbolic acid is

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