Which of the following reagents can be used to distinguish between phenol and benzoic acid?

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

Phenol and benzoic acid are distinguished by

Sodium bicarbonate reacts with salicylic acid to form:

In the reaction $C_6H_5 - X \xleftarrow[HNO_2]{Cu} C_6H_5N_2Cl \xrightarrow[\Delta]{Water} \phi - Y$,what are $X$ and $Y$ respectively?

The reaction is given as: $X \xrightarrow{Y} \text{Benzoquinone}$. Identify $X$ and $Y$ in the above reaction.