Identify the products when benzene reacts with chlorine in the...

Benzene undergoes electrophilic aromatic substitution when it reacts with halogens in the presence of a Lewis acid catalyst.

In the first case, iron ($\text{Fe}$) reacts with chlorine to form $\text{FeCl}_3$ in situ, which acts as a Lewis acid. It facilitates the generation of the electrophile ($\text{Cl}^+$), leading to the formation of chlorobenzene.
$\text{C}_6\text{H}_6 + \text{Cl}_2 \xrightarrow{\text{Fe}} \text{C}_6\text{H}_5\text{Cl} + \text{HCl}$

In the second case, anhydrous $\text{AlCl}_3$ is also a Lewis acid and similarly catalyzes the electrophilic substitution of benzene with chlorine to yield chlorobenzene.
$\text{C}_6\text{H}_6 + \text{Cl}_2 \xrightarrow{\text{AlCl}_3} \text{C}_6\text{H}_5\text{Cl} + \text{HCl}$

Note: Hexachlorobenzene ($\text{C}_6\text{Cl}_6$) is formed only when benzene reacts with an *excess* of chlorine in the presence of anhydrous $\text{AlCl}_3$ in the dark. Since excess chlorine is not mentioned, monosubstitution is considered for both reactions.

Therefore, the product in both cases (I) and (II) is chlorobenzene.

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