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Homework Help: What is the temperature at the end of the process ?

  1. Mar 9, 2010 #1
    I need help guys. I don't have any idea what to do for this question

    10 grams of oxygen gas at an initial pressure of 2.5 atm. and a temperature of 25 C
    undergoes an isochoric cooling until the pressure is halved.

    (a). What is the temperature at the end of the process?
    (b). How much work has been done in this step? Next, the gas is isothermally compressed to its original pressure.
    (c). What is the volume at the end of the compression?
    (d). How much work has been done in this step? Finally, the gas undergoes an isobaric expansion to its original volume.
    (e). How much work has been done in this step?ne in this step?
  2. jcsd
  3. Mar 9, 2010 #2


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    Homework Helper

    If you know

    [tex]\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}[/tex]

    and the volume is the same, then I think you can find T2. The final pressure P2 is half of the initial pressure P1
  4. Mar 24, 2010 #3
    ^^^^Exactly, so heres how you set it up (hope this helps)

    T2 = ( P2 / P1 ) * T1

    *Don't forget to convert to Kelvins during the calculations and remember to subtract 273 afterwards. For Part B, my question to you is : Is any Work done during a Isochoric process?


    I'm not sure how you tackle part c as the volume isn't given initially in the problem.

    I'm assuming you use : P1V1 = P2V2 & Work = -nRT*ln(Vf/Vi)

    ^^Any Ideas on how to solve part C?

    But in order to solve for the work, you need the number of moles in the 10 grams of Oxygen Gas (O2), and you need the Final & Initial Volume.
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