What are the major products $X$ and $Y$ respectively in the following set of reactions?

In the $Friedel-Crafts$ reaction,anhydrous $AlCl_3$ is used because it is ............

For isomeric hydrocarbons with molecular formula $C_9H_{12}$ that give a negative Baeyer's test,determine the total number of isomers that possess four different non-aliphatic substitution sites.

Which of the following is not formed by the ozonolysis of $o-$xylene?

The electrophile that participates in the nitration of benzene is:

Find the products $(C)$ and $(E)$ in the following reaction sequences:
$n$-propyl bromide $\xrightarrow{Na} (A)$ $\xrightarrow[Al_2O_3/773 \ K]{CrO_3} (B)$ $\xrightarrow[500 \ K]{Cl_2/UV} (C)$
$n$-propyl bromide $\xrightarrow{Na} (A)$ $\xrightarrow[Al_2O_3/773 \ K]{CrO_3} (B)$ $\xrightarrow{CH_3Cl/AlCl_3} (D)$ $\xrightarrow{Cl_2/hv} (E)$