When heated with $NH_3$ under pressure alone or in the presence of zinc chloride,phenols are converted into:

Benzoic acid on heating with $X$ gives benzene and phenol on heating with $Y$ gives benzene. What are $X$ and $Y$ respectively?

Given below are two statements:
Statement $I$: The acidic strength of monosubstituted nitrophenol is higher than phenol because of the electron-withdrawing nitro group.
Statement $II$: $o$-nitrophenol,$m$-nitrophenol,and $p$-nitrophenol will have the same acidic strength as they have one nitro group attached to the phenolic ring.
In the light of the above statements,choose the most appropriate answer from the options given below:

When phenol is treated with bromine water,the white precipitate formed is

The increasing order of $pKa$ values of the following compounds is:

Identify the trihydric phenol from the following.