The oxidation of ethylbenzene with $KMnO_4$ yields which of the following compounds?

In the reaction sequence,$C_2H_5Cl + KCN$ $\xrightarrow{C_2H_5OH} X$ $\xrightarrow{H_3O^{\oplus}, \Delta} Y$. What is the molecular formula of $Y$?

What is the final product of the following reaction sequence?
$C_4H_8$ $\xrightarrow[\text{peroxide}]{\text{HBr}} X$ $\xrightarrow[\text{(ii) } CO_2]{\text{(i) Mg/dry ether, (iii) } H_3O^+} Y$

Identify the product $C$ in the following reaction sequence:
$CH_3CN$ $\xrightarrow{Na/C_2H_5OH} A$ $\xrightarrow{HNO_2} B$ $\xrightarrow{Cr_2O_7^{2-}} C$

Which among the following reactions forms acid anhydride?

In the following reaction,the compound $B$ will be:
$C_2H_5Br$ $\xrightarrow{KCN} A$ $\xrightarrow{\text{Hydrolysis}} B$