Photochemical smog contains a mixture of primary and secondary pollutants. Primary pollutants are those which have been released directly into the photochemical smog present in the atmosphere, by the combustion of fuels; example: CO. Secondary pollutants are those which have been formed when the primary pollutant of the photochemical smog undergoes further reaction, by the heat of the sun; example: ozone. NOx and NO2 are the main primary and secondary pollutants produced respectively from motor …showed first 75 words of 735 total…

…showed last 75 words of 735 total…in a photochemical episode by building a computer model with information on the rates of reactions. - Smog chamber simulations: laboratory experiments where primary pollutants are mixed in a smog chamber and exposed to sunlight under controlled conditions, to monitor the concentration of various species as photochemical smog builds up. Reference: *1: environmental pressure by Donald miller, chemistry review, volume 9, number 4, March 2000 *2: what is photochemical smog by Gwen and mike pilling, chemistry review, volume 5 Number 5, may 1996