Cyclohexene on oxidation by $\text{KMnO}_4$ in dilute $\text{H}_2\text{SO}_4$ produces

Which of the following types of reactions is used to prepare Alkyl benzene?

$200$ mL of ethylene gas and $150$ mL of HCl gas were allowed to react at $1$ bar. Pressure to form gaseous ethyl chloride. What is the work done during the reaction?

Which of the following compounds does not decolourise $\text{Br}_2$ water?