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Homework Help: Problem, Where did I go wrong?

  1. Jan 10, 2008 #1
    1. The problem statement, all variables and given/known data

    In a portable oxygen system, the oxygen (O2) is contained in a cylinder whose volume is 0.00260 m3. A full cylinder has an absolute pressure of 1.00e7 Pa when the temperature is 299 K. Find the mass of oxygen in the cylinder.

    2. Relevant equations
    PV=nRT


    3. The attempt at a solution
    So first I solved for n in the PV=nRT eqn, (1.00e7)(.00260)/(8.31)(299K)= 935499.4 moles. After I obtained the Moles I multiplied by avadro's number (6.022e23) to get molecules, and than I multiplied by 1.6605e-27kg/atomic units to get mass. Aparently my answer is incorrect, where did I go wrong for solving this problem?
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Jan 11, 2008 #2

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    Homework Helper

    What did you multiply by 1.6605e-27kg/atomic units to get mass? Also remember the molecular weight of O2 is 32.
     
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