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CH1012
HALOGENATION
•Most important reactions in the atmosphere
involve radical reactions. eg. O3 formation
• As combustion chemistry and atmospheric reactions are very complex we will look at a more readily understood system.
Halogenation
       CH4 + Cl2      ®                      CH3Cl  + HCl
                       hn   or D > 250oC
                   (UV Light or Heat)
• This is a substitution of H by Cl which occurs by a radical chain process.
• The radical mechanism is able to break the strong C-H bonds in methane.