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Isothermal expansion hw problem

  1. Nov 28, 2006 #1
    Suppose 145 moles of a monatomic ideal gas undergo an isothermal expansion from 1.00m^3 to 4.00m^3, as shown in figure. what is the temp at the beginning and end of this process? how much work is done by the gas during the expansion?

    http://www.physics.brocku.ca/Courses/1p23/images/FG18_24.JPG [Broken]

    since it is isothermal the temperature is constant correct? :confused:
    so to solve for the temperature would i just use pv=nrt with the respective values for pressure and volume?
    and for the work done W=nrtln(vf/vi)

    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Nov 28, 2006 #2
    You have p_i and p_f, and also v_i and v_f. Can you think of a formula that uses p and v ?

    Hint: What are the units for pressure?
  4. Nov 28, 2006 #3
    so i wouldnt use pv=nrt?
  5. Nov 28, 2006 #4
    Try it out. Plug in the values of p_i and v_i into that formula.
    Then plug in the values of p_f and v_f into that formula.
    See what you get.
  6. Nov 28, 2006 #5
    im getting .332 for the temperature.
  7. Nov 28, 2006 #6
    and for the work i get 1670.42j
  8. Nov 28, 2006 #7
    Now you tell me. Is temperature constant?
  9. Nov 28, 2006 #8
    yup yup. thought it was tryin to trick me by askin the temp of beginnin and end like it was gonna be two different values.
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