What are the products when propane reacts with chlorine under UV light?

What are the products when propane reacts with chlorine under UV light?

• A. Chloropropane + Hydrogen Chloride
• B. Chloropropane + Hydrogen
• C. Chloromethane + Hydrogen Chloride
• D. Propane + Chlorine

Answer: (A)

Radical substitution of a hydrogen on an alkane by chlorine under UV light. When Cl2 is exposed to UV light, it splits into chlorine radicals. A chlorine radical abstracts a hydrogen from propane, forming hydrogen chloride and a propyl radical. That propyl radical then reacts with another Cl2 molecule to produce chloropropane and regenerate a chlorine radical, continuing the chain. Net reaction: C3H8 + Cl2 → C3H7Cl + HCl. So the main organic product is chloropropane (monochloropropane) and the inorganic product is hydrogen chloride. The other options don’t fit the typical products of this radical substitution: hydrogen gas isn’t produced here, chloromethane would require changing the carbon skeleton to a smaller molecule, and propane reacting with chlorine wouldn’t leave propane and chlorine as the final products.

Radical substitution of a hydrogen on an alkane by chlorine under UV light.

When Cl2 is exposed to UV light, it splits into chlorine radicals. A chlorine radical abstracts a hydrogen from propane, forming hydrogen chloride and a propyl radical. That propyl radical then reacts with another Cl2 molecule to produce chloropropane and regenerate a chlorine radical, continuing the chain. Net reaction: C3H8 + Cl2 → C3H7Cl + HCl. So the main organic product is chloropropane (monochloropropane) and the inorganic product is hydrogen chloride.

The other options don’t fit the typical products of this radical substitution: hydrogen gas isn’t produced here, chloromethane would require changing the carbon skeleton to a smaller molecule, and propane reacting with chlorine wouldn’t leave propane and chlorine as the final products.