Which of the following structures represents $1,3\text{-butadiene}$?

$I$. $(CH_3)_2 C=CH_2 \xrightarrow{KMnO_4 / H^{+}} X + CO_2 + H_2 O$
$II$. $CH_3-CH=CH-CH_3 \xrightarrow{KMnO_4 / H^{+}} Y$
The functional groups in $X$ and $Y$ are respectively

What is the product obtained by the reaction of $1$-butene with $HBr$ in the presence of peroxide?

Identify the major products $X$ and $Y$ in the following reactions:
$(i)$ $C_6H_5-CH=CH_2 + HBr \rightarrow X$
(ii) $C_6H_5-CH_2-CH=CH_2 + HBr \xrightarrow{\text{Peroxide}} Y$

Find the product of the reaction: $CH_3 - CH = CH_2 + HBr \rightarrow$ ?

Alkene can be prepared from alkyl halide by the following reagent: $R-CH_2-CH_2-X + \text{Base} \to \text{Alkene} + \text{Base-H} + X^-$