1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Quick question about perfect gas

  1. Jun 20, 2017 #1
    • New user has been reminded to use the Homework Help Template and show their work in the first post
    Two different gasses (Helium and Cripton) are mixed up. We can assume the compound behaves as a perfect gas only if the atoms of He and Kr have the same average value of:
    • Mass
    • Momentum
    • Velocity
    • Kinetic energy
    Which one is correct? I can't figure it out.
  2. jcsd
  3. Jun 20, 2017 #2
    Which one do you think it is and why? Let's start there.
  4. Jun 20, 2017 #3
    Obviously it's not mass (average mass can't be equal in any circumnstances), because they are at the same temperature I suppose they have the same kinetic energy, but wouldn't that happen for every kind of mixture? I can't undestand what specific property of a perfect gas is important here, what makes this mixture perfect and not real.
  5. Jun 20, 2017 #4
    I agree about mass.
    Not necessarily. Maybe after a long period of time every mixture will be in thermal equilibrium, but it doesn't have to be the case. I agree thermal equilibrium is a property which would imply the same kinetic energy. What are the other properties? Can they help us here?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook