In the presence of $NaOH$,phenol reacts with $CHCl_3$ to form $o$-hydroxybenzaldehyde. This reaction is called:

Which of the following is the most acidic?

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

Phenol reacts with $CO_2$ in the presence of sodium hydroxide followed by acidification to give a steam volatile compound $X$. The compound $X$ on treatment with acetic anhydride in the presence of a catalytic amount of $H_2SO_4$ produces $Y$. Among the following:
$(i)$ antipyretic
$(ii)$ anti-inflammatory
$(iii)$ narcotic analgesic
$(iv)$ antiplatelet
the properties shown by compound $Y$ are

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

Phenol in the presence of sodium hydroxide reacts with chloroform to form salicylaldehyde. This reaction is known as: