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Homework Help: Expanding gases

  1. Sep 26, 2007 #1
    I dont know what to research or where to start but I would like to know much energy a compressed gas a requires to turn back into a gas if it is a liquid. Is there a term I should research and a formula like with specific heat?

    The problem I am trying to solve is how much heat does X units of say freon for example absorb from the air when it goes to stap (? 14.7 psi).

    Its been a while since I have been out of grade 10 physics so excuse my stupidity....
     
  2. jcsd
  3. Sep 26, 2007 #2

    Dick

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    If you are looking at a phase change between gas and liquid you should look at stuff like 'latent heat' and 'heat of vaporization'.
     
  4. Sep 27, 2007 #3
    Thanks I have read a bit but am still stuck... Where do I start?

    I want to see how much freon needs to change state from liquid to gas to absorb about 22kJ of energy....
     
  5. Sep 27, 2007 #4

    Dick

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    Keep looking, I'm finding values like 150kJ/kg for the latent heat. So how much to do 22kJ?
     
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