When benzene is chlorinated in the presence of $FeCl_3$,the electrophile is .......

Consider the following reactions:
$C_2 H_2 \xrightarrow[500^{\circ}C]{\text{red hot iron tube}} A$
$A \xrightarrow[70^{\circ}C]{\text{conc. } HNO_3, \text{conc. } H_2 SO_4} B$
$B \xrightarrow{LiAlH_4} C_6 H_5-N=N-C_6 H_5$
$A$ and $B$ are:

What is the product formed when ethylbenzene is oxidized by $KMnO_4$?

The major product formed in the following reaction sequence is:
$C_6H_5-CHBr-CH_2Br$ $\xrightarrow[(ii) NaNH_2]{(i) alc. KOH}$ $\xrightarrow[(iii) \text{Red hot iron tube}, 873 K]{}$

The major product obtained in the given reaction is:

$C_6H_6 + 3O_3$ $\longrightarrow X \stackrel{Zn / H_2O}{}$ ${\longrightarrow} Y$; $X$ and $Y$ are respectively