acid rain

• Acid rain


  Rain with a pH lower than 6
• Rain is naturally acidic because of dissolved carbon dioxide. The pH of 'normal' rain is about 6.
• Certain pollutant gases such as Sulfur Dioxide and oxides of Nitrogen can cause the pH to drop significantly before this value.
• Sulfur dioxide


  A gas with a sharp, choking smell, produced when fossil fuels containing sulfur compounds are burned
• Formation of sulfur dioxide


  1. Fossil fuels naturally contain sulfur compounds

  2. Sulfur compounds produce sulfur dioxide when the fuel is burned
• Sulfur dioxide dissolves in water droplets in clouds

  Makes the rain more acidic than normal
• Nitrogen monoxide


  Produced when nitrogen and oxygen from the air combine at high temperatures in vehicle engines
• Formation of nitrogen monoxide


  One nitrogen molecule (N2) reacts with one oxygen molecule (O2) to make two nitrogen monoxide molecules (NO)
• Formation of nitrogen dioxide


  Nitrogen monoxide combines with oxygen in the air to form nitrogen dioxide
• NOx


  Nitrogen monoxide and nitrogen dioxide jointly
• Nitrogen dioxide is a cause of acid rain.
• Problems caused by acid rain

  • Makes lakes acidic / lowers pH of lakes
  • Plants/trees/vegetation/crops dies/stunted growth/harmed/damaged/poisoned
  • Fish/aquatic animals/pond life/marine life dies/stunted growth /harmed /damaged /poisoned
  • Limestone/marble [NOT just buildings] reacts/corrodes/is eaten away
• Solutions to acid rain

  1. Removing Sulfur from fuels

  2. 'Scrubbing' the gases from power stations and factories to remove Sulfur Dioxide and varies oxides of Nitrogen

  3. Using catalytic converters in car to convert oxides of nitrogen into harmless nitrogen gas
• Catalytic converters are not effective on short journeys as they need to become really hot to work properly.