Chlorination of Methane H H H一CH CI-CI heat or light H-H-CI H-CI H H methane chlorine chloromethane hydrogen (methyl chloride) chloride Copyright2010 Pearson Prentice Hall,Inc. Requires heat or light for initiation. The most effective wavelength is blue,which is absorbed by chlorine gas. Many molecules of product are formed from absorption of only one photon of light (chain reaction). Chapter 4 3Chapter 4 3 Chlorination of Methane • Requires heat or light for initiation. • The most effective wavelength is blue, which is absorbed by chlorine gas. • Many molecules of product are formed from absorption of only one photon of light (chain reaction)