Chlorobenzene when condensed with chloral in the presence of conc. `H_(2)SO_(4)` yields :

Phenol when condensed with phthalic anhydride in the presence of conc. H_(2)SO_(4) , yields ,

Formaldehyde condenses with phenol in the presence of dil. H_(2)SO_(4) to yield

The compound formed on heating chlorobenzene with chloral in presence of conc H_(2)SO_(4) is .

The insecticide DDT (C_(14) H_(9)Cl_(5)) is perpared by heating chlorobezene with chloral (CCl_(3)CHO) in the presence of conc. H_(2)SO_(4) . Which of the following compounds is DDT ?

Decomposition of oxalic acid in the presence of conc. H_(2)SO_(4) gives