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Homework Help: Number Density and Vrms

  1. Sep 28, 2010 #1
    The number density in a container of argon gas is 1.50×10e25 . The atoms are moving with an rms speed of 465 . What are (a) the pressure and (b) the temperature inside the container?

    Vrms=(3KbT/m)^1/2

    Na = 6.02X10^23 particles/mol

    Ar=40u

    p=F/A=(1/3)(N/V)mv^2

    pV=NKbT


    I started off with finding out how many moles there were in the container by taking 1.5e25 and dividing that by 6.02e23 and got 24.9 moles. I looked up Molar mass for Ar and got 40g per mol. The mass of the Ar is .9968 kg.

    Then I am plugging what I found for m into the first equation to solve for T but the number for T doesn't look right. Am I on the right track?
     
  2. jcsd
  3. Sep 28, 2010 #2
    So I figured out that 1 atom of Ar = 6.627E-26 and pluged it into p=(1/3)(N/V)mv^2
    and got the correct answer for Pressure.
     
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