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Homework Help: Volume of Gas At Standard Condition ? Which Gas Law ?

  1. Apr 7, 2010 #1
    1. The problem statement, all variables and given/known data

    A Sample of gas 250 mL at 37 C and 730 torr . What volume would gas occupy at standard conditions ?

    2. Relevant equations

    pv = nRT

    V2 = T2P1V1
    -------
    T1P2


    3. The attempt at a solution

    Sample Gas

    V = 250 mL ( 0.250 L )
    P = 730 torr ( .960 atm )
    T = 310 K

    Standard Condition

    T = 273
    V = 22.4 L
    P = 1 atm

    I'm confused because sample gas formula is already given and then find the gas under stand condition ?

    Do I just use standard condition formula and drop the other ones ?


    If I use pv = nRT then I get following

    v = (0.250 L / 22.4 L = .0111 mol) since STP 1 mol = 22.4 L
    p = .960 atm
    R = 0.08260 ( constant gas )
    T = 310 K

    v = (.0111 mol ) (0.08260)(310)
    --------------------------
    .960 atm

    Answer = .290 L

    The answer doesn't seem to make sense. Any correction ?
     
  2. jcsd
  3. Apr 7, 2010 #2
    I think you are only supposed to use the temperature and pressure at STP and use the equation

    PV/T = PV/T
     
  4. Apr 7, 2010 #3

    Borek

    User Avatar

    Staff: Mentor

    Good that you see that answer doesn't make sense. You are lowering temperature and increasing pressure, volume can't go up.

    --
    methods
     
  5. Apr 7, 2010 #4
    I got the answer..211 mL.. user p1v1/t2 = p2v2/t2

    close this thread.
     
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