Phenol on reaction with a mixture of conc. HNO₃ and conc. H₂SO₄ produces a compound. What is the degree of unsaturation present in the compound and nature of compound ?

What is the product "C" after following reactions -


 

The major product of the following reaction is:

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

Match the following $\mathrm{pKa}$ values.

$\mathrm{Chlorobenzene}\stackrel{\mathrm{Reaction}-\left(\mathrm{X}\right)}{\to }\mathrm{Phenol}\stackrel{\mathrm{Reaction}-\left(\mathrm{Y}\right)}{\to }\mathrm{Salicylaldehyde}$.

The reactions(s) ${}^{\text{'}}\mathrm{X}^{\text{'}}$ and${}^{\text{'}}\mathrm{Y}^{\text{'}}$ respectively are

The functional group which is formed when Phenol is made to react with Chloroform in the presence of dilute Sodium hydroxide