Heating chlorobenzene with chloral in the presence of concentrated $H_2SO_4$ yields which of the following products?

The increasing order of the rate of nucleophilic substitution reaction for the following compounds is:

Aryl halides are extremely less reactive towards nucleophilic substitution. Predict and explain the order of reactivity of the following compounds towards nucleophilic substitution:
$(I)$ $p$-nitrochlorobenzene
$(II)$ $2,4$-dinitrochlorobenzene
$(III)$ $2,4,6$-trinitrochlorobenzene

The major product for the above reaction is:

The correct sequential addition of reagents in the preparation of $3-$nitrobenzoic acid from benzene is:

Toluene reacts with halogen in the presence of iron$(III)$ chloride to give ortho and para halo compounds. The reaction is: