Chemistry ch4.txt

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Chemistry ch4.txt
2011-10-12 13:33:21

chem ch4 ut
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  1. What is energy?
    the capacity to do work or supply heat (light bulb, rocket,bomb)
  2. What is work?
    Force multiplied by the distance over which motion occurs (mowing the lawn. not pushing a wall)
  3. what is heat?
    Energy that flows from a hotter to a colder object. (ice melting)
  4. What is Temperature?
    a property of matter that determines the direction of flow of heat, or in other words a measure of how hot or cold something is
  5. how many jewles are in 1 calorie?
  6. how many jewles and kcals are in 1 Calorie
    1 kcal and 4184j
  7. What does teh First law of Thermodynamics say?
    Energy can be transformed, but it cannot be created or destroyed. it can however be lost along the way.
  8. What is the difference between potenital and kinetic energy?
    potential is stored energy while kinetic is the energy of motion
  9. in the cain of doing work what are the four differnet energy transformations?
    potential energy (fuel for burner), Kinetic energy(turbine), Mechanical energy(generator), Electrical energy.
  10. What does physics say about efficiency?
    there is a theoretical limit regardless of design
  11. What is the overall efficiency of the average coal power plant?
    ca. 42%
  12. What is Entropy? (high vs. Low?)
    A measure of randomness, High means high randomness, low means low randomness
  13. What is the second law of thermodynamics?
    the entropy of the universe tends to increase.
  14. What is exothermic?
    heat is released. (fire)
  15. What is endothermic?
    heat is absorbed (ice). also given photosynthesis as endothermic (chlorophyl)
  16. What is heat of combustion?
    the quantity of heat energy given off when a specified amount of a substance burn in oxygen?
  17. how much of the world population does the us have and what is its onsumption of oil
    5% population, 30% of oil consumed.
  18. What is a fossil fuel?
    old, dead plants essentially
  19. What is the energy content of coal?
  20. What is the energy content of wood?
  21. What is the energy content of petroleum?
  22. What is a low grade of coal called and what makes it a low grade?
    Lignite is high in oxygen and sulfur
  23. What is a high grade of coal called and what makes it high
    anthracite is low in oxygen and sulfure but hih in carbon.
  24. Why is petroleum so popular?
    more concentrated form of energy and easier to transport since it is liquid
  25. How much of our oil is imported?
  26. before what time period did the us not import its oil?
  27. What is petroleum mostly made of.
    thousands of compounds but mostly hydrocarbon (carbon and hydrogen composed)
  28. what is alkanes?
    hydrocarbons containing only single bonds(methane)
  29. What are the uses of Petroleum?
    HEating and transportation (80%), plastics, fabrics, pharmaceuticals
  30. What is cracking in gasoline making?
    breaking large molecules into smaller molecules suitable for gasoliine.
  31. How can Cracking be done in the making of gas?
    thermally or catalytically
  32. What happens after the cracking stage?
    small molecules can be combined catalytically to make larger molecules.
  33. What is a constitutional Isomer?
    Differnet compounds with the same molecular formula
  34. What is knocking?
    basially uncontrolled combustion in the engine.
  35. What does a higher octane rating mean?
    less knocking
  36. What is the OCtane rating related to?
    the amount of isooctane in gasoline
  37. Where does the term Unleaded gas come from?
    the antiknocking agent, tetraethyllead that was band in the 1970's
  38. What is the antiknocking agent used today?
    Ethanol and MTBE.
  39. What is reformulated gasoline
    Gas that contains ehtanol or mtbe and contains less hydrocarbons such as benzene
  40. What are the benifits of Refomulated gas?
    Don't evaporate as easily as regular gasoline, produce less carbon monoxide
  41. Below what level does the EPA say is safe for MTBE?
    below 40PPM
  42. Whatis teh fischer tropsch process?
    a new source of petroleum. CO is made from a process involving coal but only viable where coal is plentiful and oil is scarce
  43. What is ethanol and its energy realease?
    Is made by fermentation of corn. produces 30kj/g minus the energy used to cultivate corn
  44. What are chemiluminescence? (used where?)
    release of energy in the form of light. crime sceens
  45. What is solar energy what is some downsides?
    solar cells made from silicon that convert the sun energy to electricity. only about 15% efficent and expensive to build
  46. What is wind power and what are some downsides?
    kinetic enery from wind is converted into electricity. they are big and need wind
  47. What is geothermal and what are possible downsides?
    uses steam and heat escaping from planet to produce electricity. limited to specific geography.
  48. What is bio gas?
    deconmposign trash and sewage produces CH4 which can be colected at land fields.