1. Acid Rain

2. Acid Precipitation Click Here Click Here Damage caused by acid rain
Click on the SO2 and NOx letters to view a map of the United States and the levels of these pollutants.
Acid rain is rainfall whose pH is less than 5.6 due to dissolved carbon dioxide, which reacts with water to give the weak acid carbonic acid.
Source of the increased acidity in rain due to the presence of large quantities of sulfate (SO42-) and nitrate (NO3-) ions, which come from nitrogen oxides and sulfur dioxide produced both by natural processes and by the combustion of fossil fuels
These oxides react with oxygen and water to give nitric acid and sulfuric acid.
Damage caused by acid rain
1. Dissolves marble and limestone surfaces due to a classic acid-base reaction
2. Accelerates the corrosion of metal objects
3. Decreases the pH of natural waters
4. Biological effects

3. Formation of Sulfuric Acid
SO2(g) + H2O(l) H2SO3(aq) +
2SO2(g) + O2(g) SO3(g)
Catalyzed by atmospheric dust
Sulfuric acid +
SO3(g) + H2O(l) H2SO4(aq)
SO2(g) + H2O2(l) H2SO4(aq)
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 302

4. Hydrogen ion concentration as pH from measurements
made at the field laboratories during 2003
National Atmospheric Deposition Program/National Trends Network
made at the Central Analytical Laboratory, 1999
The progressively darker red areas on the map indicate the lowest pH levels
and areas most prone to problems from acid rain.
Figure courtesy of the National Atmospheric Deposition Program, Champaign, Ill.

5. Acid Rain Estimated sulfate ion deposition, 1999
Smoke stacks pollute SO2
into the atmosphere. This
combines with water to form
acid rain.

6. SO4 Levels

7. Nitrate Ion Concentrations
1985
1986
1984

8. Nitrate Ion Concentrations
1986
1987
1985

9. Nitrate Ion Concentrations
1987
1988
1986

10. Nitrate Ion Concentrations
1988
1989
1987

11. Nitrate Ion Concentrations
1989
1990
1988

12. Nitrate Ion Concentrations
1990
1991
1989

13. Nitrate Ion Concentrations
1991
1992
1990

14. Nitrate Ion Concentrations
1992
1993
1991

15. Nitrate Ion Concentrations
1993
1994
1992

16. Nitrate Ion Concentrations
1994
1995
1993

17. Nitrate Ion Concentrations
1995
1996
1994

18. Nitrate Ion Concentrations
1996
1997
1995

19. Nitrate Ion Concentrations
1997
1998
1996

20. Nitrate Ion Concentrations
1998
1999
1997

21. Nitrate Ion Concentrations
1999
2000
1998

22. Nitrate Ion Concentrations
2000
2001
1999

23. Nitrate Ion Concentrations
2001
2002
2000

24. Nitrate Ion Concentrations
2002
2003
2001

25. Nitrate Ion Concentrations
2003
2004
2002

26. Sulfate Ion Concentrations
1985
1986
1984

27. Sulfate Ion Concentrations
1986
1987
1985

28. Sulfate Ion Concentrations
1987
1988
1986

29. Sulfate Ion Concentrations
1988
1989
1987

30. Sulfate Ion Concentrations
1989
1990
1988

31. Sulfate Ion Concentrations
1990
1991
1989

32. Sulfate Ion Concentrations
1991
1992
1990

33. Sulfate Ion Concentrations
1992
1993
1991

34. Sulfate Ion Concentrations
1993
1994
1992

35. Sulfate Ion Concentrations
1994
1995
1993

36. Sulfate Ion Concentrations
1995
1996
1994

37. Sulfate Ion Concentrations
1996
1997
1995

38. Sulfate Ion Concentrations
1997
1998
1996

39. Sulfate Ion Concentrations
1998
1999
1997

40. Sulfate Ion Concentrations
1999
2000
1998

41. Sulfate Ion Concentrations
2000
2001
1999

42. Sulfate Ion Concentrations
2001
2002
2000

43. Sulfate Ion Concentrations
2002
2003
2001

44. Sulfate Ion Concentrations
2003
2004
2002

45. Coal Burning Power Plant
Coal-fired units produce electricity by burning coal in a boiler to heat water to produce steam. The steam, at tremendous pressure, flows into a turbine, which spins a generator to produce electricity. The steam is cooled, condensed back into water, and returned to the boiler to start the process over.
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

46. Statewide Coal-Fired Power Plants
Legend
Existing Power Plant
Proposed Power Plant
City

47. Coal Burning Power Plant

48. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

49. CO2 (g) H2O (l) H2CO3 (aq) Carbon dioxide Water Carbonic acid
Weak acid
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

50. Carbon dioxide
Water
Carbonic Acid

52. Carbon dioxide
Water

61. Carbonic Acid
Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.