The oxidation of benzene by $V_2O_5$ in the presence of air and high temperature produces

What is the expected order of reactivity of the following compounds in electrophilic chlorination $(Cl_2 + FeCl_3)$? (more reactive $ > $ less reactive)
$I: C_6H_5CH_2CO_2H$
$II: C_6H_5N(CH_3)_2$
$III: C_6H_5OCOCH_3$
$IV: C_6H_5CCl_3$

Identify $X$ in the following reaction.

Designate whether each of the following compounds is aromatic or not aromatic.

The structures of $A$ and $B$ formed in the following reaction are : $[Ph = -C_6H_5]$

In which of the following reactions,$t$-butyl benzene is formed?
$1.$ Benzene $+ t$-butyl chloride $\xrightarrow{AlCl_3}$
$2.$ Benzene $+ (CH_3)_2C=CH_2 \xrightarrow{BF_3/HF}$
$3.$ Benzene $+ t$-butyl alcohol $\xrightarrow{H_2SO_4}$
$4.$ Benzene $+$ butanoyl chloride $\xrightarrow{AlCl_3}$ $\xrightarrow{Zn/Hg, HCl}$