Chapter 25, Problem 25.13P

Interpretation Introduction

Interpretation:

A termination step for the reaction in Equation 25-17 that is different from the ones shown in Equation 25-20 is to be drawn.

Concept introduction:

Halogen molecules undergo homolysis when irradiated with UV light to produce two radical atoms. Homolysis is the type of bond dissociation where each atom gets one of the bond electrons. An unpaired electron present in radical of atom or molecule. It is highly unstable, and therefore a highly reactive species. This homolytic dissociation is called initiation.

Being reactive, a radical will react with other species present. This produces another radical, which can continue the reaction is a step called propagation. The reaction is generally branched as each initiation step produces two radicals. The propagation steps carry on as long as radicals are present, and may be completed by a reaction between any two radicals.