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Homework Help: Thermal processes

  1. Sep 17, 2008 #1
    1. The problem statement, all variables and given/known data

    A 1.20mol sample of an ideal monatomic gas, originally at a pressure of 1.00 atm, undergoes a three-step process: (1) it is expanded adiabatically from T1 = 592k to T2 = 390k ; (2) it is compressed at constant pressure until its temperature reaches T3; (3) it then returns to its original pressure and temperature by a constant-volume process.

    Determine T3.

    2. Relevant equations

    E= 3/2 nRT

    3. The attempt at a solution

    So from T1 to T2, change in energy is -3022.97J. E at T1 8859.398J and E at T2 is 5836.4284J. From T2 to T3, it's isobaric. i found initial volume (at T1) to be .0583m^3. how do i go from here?
  2. jcsd
  3. Sep 17, 2008 #2
    bbbbump :(
  4. Sep 17, 2008 #3
    So what is your question exactly? You might want to work backwards from T1 to help you determine T3 if thats what your after.
  5. Sep 17, 2008 #4


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    What does step 3 tell you about the volume at the end of step (2)?
  6. Sep 17, 2008 #5
    the volume at the end of step (2) is the same volume as the volume at T1.
  7. Sep 17, 2008 #6


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    So now you just need to find the pressure at the end of step (2), and you'll have T_3.
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