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Homework Help: Kinetic Theory of Gases- no. of collisions

  1. Jan 6, 2016 #1
    1. The problem statement, all variables and given/known data
    One mole of oxygen at 27°C and at one atmospheric pressure is enclosed in a vessel.
    Assuming the molecules to be moving with Vrms, find the number of collisions per second which the molecules make with 1 m2 area of the vessel wall.

    2. Relevant equations
    vrms = √(3RT/M)
    PV = nRT

    3. The attempt at a solution
    I want to find the total number of collisions that the molecules make with a cube of side 1m and divide that by 6 to get the no. of collisions with one face.
    I know how to calculate pressure (using momentum etc), which gives the equation P = ⅓ ( mN/V ) (vrms)2 where m is the mass of one molecule, N total no. of molecules, V volume.
    I don't know how to combine all this information.
  2. jcsd
  3. Jan 6, 2016 #2


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    Gold Member

    You combine it ONE step at a time. Your first error: you assume a 1 meter cube. Why?
  4. Jan 6, 2016 #3
    Okay I won't. I'll assume a volume V. What next?
  5. Jan 6, 2016 #4
    Also, do I need to even assume that it's a cube? How about I just assume a randomly shaped vessel with volume V?
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