Phenol,when it first reacts with concentrated sulphuric acid and then concentrated nitric acid,gives:

The major product of the following reaction sequence is:
Aniline $\xrightarrow[(i) NaNO_2, HCl, 273-278K]{(ii) H_2O, warm} \text{Product}$ $\xrightarrow[(iv) NaOH]{(iii) Br_2, (excess)} \text{Product}$ $\xrightarrow{(v) CH_3I} \text{Final Product}$

Which among the following compounds has the highest melting point?

Which of the following compounds has the most acidic nature?

What are $X$ and $Y$ in the following reactions?

By passing vapours of phenol over heated $zinc$ dust will produce :