ch17f

http://www.sciencewithmrmilstid.com/wp-content/uploads/acid_rain.gif - Every year, acid rain causes hundreds of millions of dollars' worth of damage throughout the world - It damages stone buildings and statues and is toxic to vegetation and aquatic life - The average pH of rain in the northeastern US is 4.3 - Atmospheric CO2 alone could only cause the pH to drop to ~5.5, so SO2 must also be present - Sources of SO2: * burning of fossil fuels in industry, power plants, and homes ---* smelting (extracting) metals ---* 2ZnS(s) + 3O2(g) → 2ZnO(s) + 2SO2(g) ---* volcanoes - 50 to 60 million tons of SO2 are released into the atmosphere every year - SO2 is oxidized to H2SO4 through a complex process that is not well understood: - OH + SO2 → HOSO2 - HOSO2 + O2 → HO2 + SO3 - SO3 + H2O → H2SO4 - Acid rain can corrode limestone and marble (CaCO3): - CaCO3(s) + H2SO4(aq) → CaSO4(s) + H2O(l) + CO2(g) - Sulfur dioxide can directly attack calcium carbonate: - 2CaCO3(s) + 2SO2(g) + O2(g) → 2CaSO4(s) + 2CO2(g) - Acid rain is also caused by carbon monoxide, chlorofluorocarbons, lead, nitrogen oxides, ozone, - particulate matter, and volatile organic compounds
 * Chapter 17 Section F: Acid Rain **

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