Question

When propene is heated at 400°C in the presence of chlorine, it gives ______.

Options

• polyvinyl chloride

• no reaction

• 1, 2-dichloropropane

• allyl chloride

Answer 1

When propene is heated at 400°C in the presence of chlorine, it gives allyl chloride.

Explanation:

At high temperature (400°C), chlorine does not add across the double bond (as it would at room temperature), but instead undergoes free radical substitution at the allylic position (the carbon next to the double bond). The hydrogen at this position is replaced by chlorine to form allyl chloride.