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Homework Help: Kinetic Energy Problem

  1. Jan 6, 2010 #1
    Please Help! Kinetic Energy Problem

    1. The initial pressure in an ideal gas is 1.40 atm when its temperature is 299 K. The temperature is increased to 315 K and the volume is increased to 1.29 times its initial value. Calculate the final pressure.

    2. R = 8.31 J/molK

    PLEASE HELP!

    THANKS IN ADVANCE!!
     
  2. jcsd
  3. Jan 6, 2010 #2

    ideasrule

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    Re: Please Help! Kinetic Energy Problem

    What have you tried already?
     
  4. Jan 6, 2010 #3
    Re: Please Help! Kinetic Energy Problem

    Thats just the thing. I cannot figure out what formula to use. The formula's I have are PV=nRT and PV=NKbT... none of the formulas I was given seem to be valid for a "change in temp/volume"
     
  5. Jan 6, 2010 #4

    ideasrule

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    Re: Please Help! Kinetic Energy Problem

    Try writing out PV=nRT for both the "before" and "after" situations. You'll be able to solve for the final pressure from there, even though you don't know n (and don't need to know R).
     
  6. Jan 7, 2010 #5
    Re: Please Help! Kinetic Energy Problem

    Make 2 equations and solve by dividing the equations. Cancel out the same unknown.
     
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