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Homework Help: Rms speed

  1. Dec 12, 2009 #1
    1. A canister containing 150kg of an ideal gas has a volume of 8 m^3. If the gas exerts a pressure of 5*10^5 Pa, what's the rms speed of the modecules?



    I can't get the temperature of the canister...
     
  2. jcsd
  3. Dec 12, 2009 #2

    ideasrule

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    You don't need it. You have PV=nRT, so T=PV/nR. Leave it as that and continue solving the problem. Eventually, you should get a "nm" in your solution. What's this equal to?
     
  4. Dec 12, 2009 #3
    so nm equals the #of moles times its mass, what isn't the #of moles still unknow?
     
  5. Dec 12, 2009 #4

    ideasrule

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    nm is the #of moles times the molar mass (mass per mole). What's # of moles times the mass per mole?
     
  6. Dec 12, 2009 #5
    I use the formula v = square root of(3kT/m), which k stands for boltzmann's constant and m stants for the mass of molecule.
     
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