This series of reactions involves the conversion of ethene $C2H4$ to carbon dioxide $CO2$ through a series of intermediates. Here is the step-by-step breakdown of the reactions:

C2H4 undergoes halogenation with HCl to form C2H5Cl $ethylchloride$.C2H5Cl is then treated with a strong base, such as NaOH, to form C2H5OH $ethanol$.Ethanol can further be oxidized to form acetaldehyde $C2H4$ and then to carbon dioxide $CO2$ through combustion.

Overall, the conversion of ethene to carbon dioxide involves halogenation, alcohol formation, and oxidation steps.