The compound formed on heating chlorobenzene with chloral in the presence of concentrated sulphuric acid is:

Chloral (${\text{CCl}}_3\text{CHO}$) reacts with two molecules of chlorobenzene in the presence of concentrated ${\text{H}}_2{\text{SO}}_4$ to produce $p,p^{\prime }$ -dichlorodiphenyltrichloroethane, commonly known as $\text{DDT}$.