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Confused - Pressure in a canister???

  1. Jul 15, 2015 #1
    A manufacturer quotes a standard co2 canister contains 16g of co2 at a volume of 20cm^3.

    So I need to calculate the pressure in the canister....

    Using ideal gas law

    P = nRT/V
    n = 0.364mol (16 of co2)
    R = 8.314 J/Kmol (universal gas constant)
    T = 294k (gas is at room temp 21 deg C)
    V = 20cm3 (volume of canister as quoted)

    P = 444 Bar

    However the manufacturer quotes the canister pressure to be 60Bar! This seems a bit more realistic to me but I've no idea how this could be the case.

    Any thoughts to clear up the confusion?
  2. jcsd
  3. Jul 15, 2015 #2
    Its must be cubic meter.Convert 20 cm3 to meter3
  4. Jul 15, 2015 #3
    Good point, but I already did the conversion to m^3 in the calculation to give 444Bar.
  5. Jul 15, 2015 #4
    I dont know chemical very well but maybe theres another formula to calculate pressure.Maybe CO2 supposed to be non-idel gas.
    Your equation seems correct.
  6. Jul 15, 2015 #5
    hum, I don't think it matters if the gas is 'ideal' or not. The manufacturer quoting 16g of co2 in a 20cm^3 canister stored at room temperature. I'm confused as to where the 60 Bar quote comes from.
  7. Jul 15, 2015 #6
    Perhaps the CO2 is not all a gas under pressure and the pressure is the vapor pressure at a given temperature.
  8. Jul 15, 2015 #7
    You wrote it isnt it ?
  9. Jul 15, 2015 #8
    Theres only two option.First option this is not an idel gas.Ideal gas make the equation simpler but maybe theres another type of equation which I said before.
    Second think As you said its not 60 bar

    Theres no other option cause our solution is correct.
  10. Jul 15, 2015 #9


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