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!

Diffusion, isn't this the formula I'm supposed to be using?

  1. Nov 25, 2007 #1
    A sample of an unknown gas takes 434 s to diffuse through a porous plug at a given temperature. At the same temperature, N2(g) takes 175 s to diffuse through the same plug. What is the molar mass of the unknown gas?

    [tex]\frac {Rate_{A}}{Rate_{B}} = \sqrt {\frac {\mathcal{M}_{B}}{\mathcal{M}_{A}}}[/tex]
  2. jcsd
  3. Nov 25, 2007 #2
    faster vs slower gas

    which one is the faster gas? would the faster gas be the lighter or heavier gas?

    try your equn this way

    faster gas = sqrt (Mslower/Mfaster)
    slower gas
  4. Nov 25, 2007 #3
    Yes the formula is correct but how are you using it? That is show what your getting
  5. Nov 25, 2007 #4
    thanks, the answer doesn't even appear as one of the choices.
  6. Nov 25, 2007 #5
    what did you get as an answer?
    Last edited: Nov 25, 2007
  7. Nov 25, 2007 #6
    i appreciate your help but i was really only concerned about the equation, thanks.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook