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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.
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