1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is the mass of the helium present - Thermodynamics

  1. Jan 10, 2006 #1
    A sample of helium behaves as an ideal gas as energy is added by heat at constant pressure from 273 K to 383 K. If the gas does 23.0 J of work, what is the mass of helium present?

    I tried this and think u use m=Q/c*change in T, but not sure where to go from there
     
  2. jcsd
  3. Jan 10, 2006 #2
    The expression for the work done by the gas is:
    [tex]dW=PdV[/tex]
    Since there is constan pressure we can write:
    [tex]V=\frac{nRT}{P}[/tex]
    [tex]dV=\frac{nR}{P}dT[/tex]
    So
    [tex]dW=nRdT[/tex]
    and
    [/tex]W=\int_{T_1}^{T_2}nRdT[/tex]
    Do the integral, use the molar mass of He to convert the # of moles of He to the mass, and then solve for the mass.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: What is the mass of the helium present - Thermodynamics
  1. Helium Hamiltonian (Replies: 1)

  2. Helium radius (Replies: 0)

  3. Excited helium (Replies: 1)

Loading...