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Homework Help: CHEMISTRY: Partial Pressure

  1. Oct 6, 2008 #1
    1. The problem statement, all variables and given/known data
    The air in a bicycle tire is bubbled through water and collected at 25 [tex]^\circ {\rm C}[/tex]. If the total volume of gas collected is 5.25 L at a temperature of 25 [tex]^\circ {\rm C}[/tex] and a pressure of 734 torr, how many moles of gas was in the bicycle tire?

    2. Relevant equations
    PV = nRT

    R = .08206

    3. The attempt at a solution

    1. Convert 734 torr to atm

    734/760 = .966 atm

    2. Convert 25 [tex]^\circ {\rm C}[/tex] to K = 298.15 K

    3. Plug those all in:

    [tex]n=\frac{(.966 atn)(5.25 L)}{(.08206)(298.15 K)}[/tex]

    I got n=.207 moles, but the online assignment says I got it wrong.
  2. jcsd
  3. Oct 6, 2008 #2


    User Avatar

    Staff: Mentor

    0.207 is a correct number of TOTAL moles. Part of this total is water vapour.
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