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Thermodynamics Question

  1. Oct 7, 2012 #1
    I have this problem:

    Two (2) kilograms of Nitrogen gas at 600 K and 10 atm are allowed to expand such that they end up occupying three (3) times the initial volume and providing 50% of the isobaric work.

    mass = 2000 g
    temp1 = 600 K
    pressure1 = 1013250 Pa
    gasC = 8.3144621
    n = mass/28.0134 = 71.3944 mol
    v1 = (n*gasC*temp1)/pressure1 = 0.351506 m^3
    v2 = 3*v1 = 1.05452 m^3

    w = p1*(v2 - v1) = 712327 J

    I have to determine v2, temp2, and pressure2 and characterize the process. Where I'm confused is the 50% of isobaric work part. If the system is isobaric wouldn't all of the work being done be a result of the change in volume? Or am I missing something related to a change in temperature that would affect the work being done?

    Any help would be greatly appreciated.
    Last edited: Oct 7, 2012
  2. jcsd
  3. Oct 8, 2012 #2


    User Avatar
    Gold Member

    An isobaric process is a thermodynamic process in which the pressure stays constant.
    Your question does not say the process is isobaric, but that the work is 50% of that had the process been an isobaric expansion.
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