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Homework Help: Kinetic Theory Problem

  1. Jan 7, 2010 #1
    1. The problem statement, all variables and given/known data
    A sample of an ideal gas is at a temperature of 320 K. The rms molecular speed at this temperature is measured as 1631 m/s. Calculate the mass of a molecule of this gas

    2. Relevant equations

    rms velocity , u = √(3RT/M )

    3. The attempt at a solution

    Given u = 1631 m / s
    Temperature , T = 320 K
    R = gas constant = 8.314 J/ mol . K
    Molar mass of the gas molecule , M = 3RT / u 2
    = 3 * 10^-3 Kg / mol
  2. jcsd
  3. Jan 7, 2010 #2


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    Homework Helper

    Right. You can convert to kg/molecule now, or you can use u=sqrt(3kT/m) instead of u=sqrt(3RT/M) and get the answer directly.
  4. Jan 7, 2010 #3
    so do i just multply by 6.02e23?
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