Science Final

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Science Final
2011-12-06 14:32:09
Environmental Science

Environmental Science
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  1. The earth and Venus have average temperatures that are quite different. What are these temperatures and what causes the difference?
    Venus - 400 degrees. Earth 15 degrees. Carbon dioxide warms both Venus and Earth. Without it we would freeze.
  2. One of the pioneers in understanding global warming was John Tyndall—what was he able to demonstrate concerning global warming.
    Carbon dioxide and water vapor are greenhouse gases. They absorb IR radiation.
  3. How do the carbon dioxide levels in the atmosphere today compare to the levels in the earth’s early years? How does today’s average global temperature compare to temperatures of the early Earth?
    The carbon dioxide levels are much higher and so is the temperature.
  4. What is the fate of the radiation that the earth receives from the sun? What happens to uv radiation from the sun? What role do greenhouse gases play in reference to infrared radiation? Why is this role so important.
    U.V. radiation is absorbed by ozone. I.R. traps the radiation. This is important so we do not freeze.
  5. How does infrared radiation compare to uv radiation in terms of how it affects molecular structure. While infrared
    radiation cannot break chemical bonds, what can it do.
    U.V. radiation breaks molecules apart, it is stronger than I.R. I.R. radiation causes molecules to vibrate.
  6. What are the major contributors to the enhanced greenhouse effect? List at least 5.
    Carbon dioxide, Nitrigen Oxide, Ozone, water vapor, CFC's, and Methane.
  7. How do each of the following affect the amount of carbon dioxide in the atmosphere: respiration, photosynthesis, deforestation, reforestation, combustion of fossil fuels
    Respiration - Increases. Photosynthesis - Decreases. Deforestation - Increases. Reforestatiion - Decreases. Combustion of fossil fuels - Increases.
  8. In reference to greenhouse gases: What is GWP?
    Global Warming Potential - Tells how well aa molecule absorbs I.R. radiation.
  9. What is global atmospheric lifetime?
    Characterizes the time required for a gas added to the atmoshpere to be removed.
  10. What are the various sources of atmospheric methane?
    Rock fissures, decaying wetlands, landfills, rice paddies, ruminants, and termites.
  11. What is an aquifer?
    An underground resivior
  12. What is ground water?
    Fresh water found underground
  13. What is surface water?
    Fresh water found in lakes, streams, and rivers.
  14. List the physical characteristics of water that make it a special compound?
    Liquid at room tempurature, has a high boiling point, and expands when it freezes.
  15. Explain the density difference between ice an water—what causes this difference?
    Ice is less dense than water due to hydrogen bonding.
  16. Why is the boiling point of water so high?
    Because hydrogen bonds are so strong. It takes a long time to break them apart.
  17. Explain the concept of hydrogen bonding between water molecules.
    An electrostatic attraction between an H atom in one molecule and the O atom in a different molcule.
  18. Some contaminants of water pose a chronic health risk while others pose an acute health risk. Acute health risks are of immediate concern, while chronic health risks are more long term. Which of the following are acute health risks: nitrates, Giardia, Cryptosporidium
    Giardia and Cryptosporidium
  19. Which cations contribute to water hardness?
    Cations with a +2 charge
  20. What two common chemicals are used to treat municipal water to bring about flocculation and removal of particulate matter?
    Aluminum sulfate and calcium hydroxide
  21. What is reverse osmosis?
    Uses pressure to forg the movement of water through a semipermeable membrane from a solution that is more concentrated to a solution that is less concentrated.
  22. What is desalination?
    Any process that removes ions from salt water.
  23. What is distillation?
    A separation process in which a liquid solution is heated and the vapors are condensed and collected.
  24. What is an acid? Examples?
    Any substance that releases hydrogen ions in an aqueous solution. Lemon juice and coke.
  25. What is a base? Examples?
    Any substance that releases/forms OH- in an aqueous solution. Ammonia and baking soda.
  26. What does ph measure? What is the range of the pH scale? What is the difference in hydrogen ion concentration for each pH unit on the scale?
    Measures the concentration of the H+ ions present in a solution. The range is 0-14. A power of 10 change.
  27. Normal rain is slightly acidic. What is its pH? What causes the pH to be on the acidic side?
    5.3 pH. Water reacts with carbon dioxide in the atmosphere forming carbonic acid, a weak acid
  28. Are SO2 and NO2 acids? Why are they called acid anhydrides?
    They are not unless formed with water. They are acid anhydrides because they need water to be an acid.
  29. What are the major anthropogenic sources of SO2?
    Burning of coal
  30. Acid rain or acid smog in Los Angeles is caused primarily by NO2 What is the main source of NO2?
    Internal combustion. Burning of gasoline in cars.
  31. Acid rain is known to deteriorate marble statues? What are the products of this chemical reaction? Note: Calcium carbonate is a base in this reaction, since it accepts hydrogen ions.
    Ca2+ + CO2 + H20
  32. List the possible effects of acid rain on human health.
  33. Which causes more damage to structures and living things---acid precipitation (rain, snow,etc.) or acid deposition (aerosols, haze, smog, etc.)?
    Structures - Precipitation. Living things - Acid deposition
  34. Lakes of the Midwest don’t seem to be affected by acid rain to a great degree—explain.
    They are limestone lakes. They have a high acid neutrualizing capacity.
  35. Lakes in New England and upstate New York are impacted greatly by acid rain. Why? What happens when the ph ofone of these lakes drops to 5?
    They are granite lakes. When pH goes below 5 all aquatic life disappears.