Which compound is formed when chlorobenzene is heated with chloral in the presence of concentrated sulfuric acid?

Explain the mechanism of nucleophilic substitution reaction of $m$-nitrochlorobenzene at ortho and para positions.

The product $(A)$ of the reaction is:

The major product formed in the Friedel-Crafts acylation of chlorobenzene is $p-$chloroacetophenone. Identify the correct structure of the major product.

Arrange the following groups in increasing order of reactivity towards electrophilic nitration reaction: $C_6H_6, C_6H_5Cl, C_6H_5COOH, C_6H_5NH_2$.

Assertion : The presence of nitro group facilitates nucleophilic substitution reactions in aryl halides.
Reason : The intermediate carbanion is stabilized due to the presence of nitro group.