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Pressure of a gas in atmospheres at different temperatures

  1. Oct 26, 2011 #1
    A chemist measured the pressure of a gas in atmospheres at different temperatures in
    °C:
    Temp (°C) -136 -25 0 25 100 273
    Pressure (atm) 0.50 0.91 1.00 1.09 1.37 2.00
    Can you predict the temperature at which the pressure would equal zero?
     
  2. jcsd
  3. Oct 26, 2011 #2

    BruceW

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    Homework Helper

    Its a complicated question, because the relationship between temperature and pressure in the atmosphere is not linear at all. The atmosphere has several different 'sections' as you go higher up, so the behaviour changes.
     
  4. Oct 26, 2011 #3
    ok Bruce, but in your opinion, what would your prediction be and please explain how u got to ur answer.
    this prob was actually posted to me by a webhosting company, i applied there for a job. so i really need to nail this.
     
  5. Oct 26, 2011 #4
    never took physics, guess the physics gods are taking revenge now :-(
     
  6. Oct 26, 2011 #5

    Doc Al

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    I don't think the question has anything to do with the atmosphere (which would certainly complicate things) but just that it measures the gas pressure in atmospheres.

    My suggestion: Change to an absolute scale of temperature (°K instead of °C) and draw a plot of pressure vs temperature.
     
  7. Oct 26, 2011 #6
    You lost me. I understand plotting, but Id still have to come up with the the temperature at which the pressure would equal zero..
     
  8. Oct 26, 2011 #7

    Doc Al

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    Did you do what I suggested?
     
  9. Oct 26, 2011 #8

    BruceW

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    OH! Ah, I see you were only mentioning 'atmospheres' as a measure of the pressure. Sorry, I totally misunderstood you.
     
  10. Oct 26, 2011 #9
    Honestly, I dont know how. Never took physics.
     
  11. Oct 26, 2011 #10

    BruceW

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    Doc Al has the right idea. You should plot temperature on one axis and pressure on the other, then see what you get. From this you might be able to infer the temperature at which pressure is zero.
     
  12. Oct 26, 2011 #11

    Doc Al

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    Staff: Mentor

    If you do nothing else, just make a plot of pressure versus temperature and see what it looks like.

    (You don't even really need to change the temperature scale, since they are proportional.)
     
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