Identify the major product obtained in the following reaction.
Chlorobenzene $\xrightarrow[\text{Anhydrous } FeCl_3]{Cl_2}$ major product

Rank the following compounds in order of decreasing rate of reaction with alkoxide ion $(CH_3CH_2O^{-})$ in a nucleophilic aromatic substitution reaction:
$1$. $1$-bromo-$2$-nitrobenzene
$2$. $1$-bromo-$3$-nitrobenzene
$3$. $1$-bromo-$2,4$-dinitrobenzene
$4$. $1$-bromo-$3,4$-dinitrobenzene

The reaction of aryl halide with sodium metal in dry ether to give biphenyl is known as

The major product obtained on the monobromination (with $Br_2/FeBr_3$) of the following compound $A$ 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 increasing order of nitration of the following compounds is:
$(A)$ Aniline
$(B)$ Chlorobenzene
$(C)$ Anisole
$(D)$ Toluene