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CH3041
THE HYDROXYL
RADICAL I
• The major
permanent gases in the troposphere are quite unreactive and have long
lifetimes.
• The hydroxyl
radical OH. plays a dominant role
in the reactive chemistry of the troposphere. [OH.] = 10-5 ppbv v. reactive
• Formation: O* + H2O
® 2OH.
• O* an excited
state of atomic oxygen called
singlet oxygen. O3 + hn(UV-B) ® O2* + O*
singlet oxygen. O3 + hn(UV-B) ® O2* + O*
• Other chemicals involved in the
formation
of O* and OH. are N2, NO (nitric oxide), NO2 (nitrogen dioxide) and O2.
of O* and OH. are N2, NO (nitric oxide), NO2 (nitrogen dioxide) and O2.
