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Effusion rates please help!

  1. Sep 22, 2004 #1
    effusion rates....please help!

    Could someone please explain to me how to do this question...
    The rate of effusion of a particular gas was measured to be 24.0 mL/min. Under the same conditions the rate of effusion of pure methane gas, (CH4) is 47.8 mL/min. What is the molar mass of the unknown gas?
  2. jcsd
  3. Sep 23, 2004 #2


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    Effusion rates are indirectly proportional with the molar mass; if the molecule is bigger, it can't move fast. So the particular gas has a greater molar mass.

    Calculate methane's molar mass by taking C:12, and H:1 grams/mol, and find the unknown gas' molar mass.

    Last edited: Sep 23, 2004
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