Biogeochemical Cycles
  Spheres of B. Cycles
  Nitrogen Properties
  Simple Nitrogen Cycle
  Human Influences
  Spheres of the N Cycle
  Choose a Sphere



Nitrogen Dioxide (NO2)

NO2 is produced by combustion, degradation of organic matter, and oxidation of NO. It is one of the few colored gases and gives a brownish tint to polluted air. NO2 is visible at concentrations as low as 1 ppmv, and is oxidized to HNO3 in the atmosphere. It also hydrolyzes and disproportionates to give HNO3 and HNO2.

NO2 is slightly soluble in water. The Henry's law constant for NO2 is 1.0x10-2 mol/atm. The partial pressure of NO2 in the atmosphere is 1-5x10-9 atm.

Suggested Reading:

Cotton, F. A., Wilkinson, G. 1972. Advanced Inorganic Chemistry, 3rd ed. New York:Wiley.

Greenwood, N. N., Earnshaw, A. 1984. Chemistry of the Elements. Oxford:Pergamon.

Morel, F. M. M., Hering, J. G. 1993. Principles and Applications of Aquatic Chemistry. New York:Wiley.

Wark, K., Warner, C. F. 1981. Air Pollution: Its Origin and Control. New York:Harper and Row.