When a haloalkane is subjected to X2 under UV light, what products are formed?

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Multiple Choice

When a haloalkane is subjected to X2 under UV light, what products are formed?

Under UV light, diatomic halogen X2 splits into halogen radicals X•. These radicals drive a radical chain with the haloalkane: an X• can remove the halogen atom from the haloalkane, giving an alkyl radical and X2. The alkyl radical then typically picks up a hydrogen atom from a donor (solvent or another molecule) to form the corresponding alkane, while the halogen radicals recombine to form more X2. So the overall outcome is that the haloalkane is converted to an alkane, and X2 appears as a product (as halogen atoms recombine). The other options would require different reagents or reaction conditions (elimination to form an alkene, oxidation to alcohol or aldehyde), which aren’t driven by simple photolysis of X2 with a haloalkane.

Under UV light, diatomic halogen X2 splits into halogen radicals X•. These radicals drive a radical chain with the haloalkane: an X• can remove the halogen atom from the haloalkane, giving an alkyl radical and X2. The alkyl radical then typically picks up a hydrogen atom from a donor (solvent or another molecule) to form the corresponding alkane, while the halogen radicals recombine to form more X2. So the overall outcome is that the haloalkane is converted to an alkane, and X2 appears as a product (as halogen atoms recombine). The other options would require different reagents or reaction conditions (elimination to form an alkene, oxidation to alcohol or aldehyde), which aren’t driven by simple photolysis of X2 with a haloalkane.

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