Which of the following chlorides is the least reactive towards hydrolysis?

Presence of a nitro group in a benzene ring

Arrange the following compounds in order of increasing dipole moment.
$(I)$ Toluene
$(II)$ $m$-dichlorobenzene
$(III)$ $o$-dichlorobenzene
$(IV)$ $p$-dichlorobenzene

Identify the product $Y$ in the given reaction sequence:
Benzene $\xrightarrow[Conc. H_2SO_4]{Conc. HNO_3} X$ $\xrightarrow[FeCl_3]{Cl_2} Y$

What will be the major product in the following mononitration reaction?

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