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Calculation of pressure

  1. Oct 11, 2012 #1
    i am an intern in a company looking to find the solution to a problem.

    I have an experimental setup with a 150cm3 can of chemical precursor with a evacuated pressure of 0.01 Torr
    We are introducing N2 from a 20 psi line with a stop valve for a duration of 20ms.
    The question is what is the pressure in the bottle after 20ms of N2 introduction?

    I am not too sure what the approach is.
    I tried to do a simple PV = nRT but it does not get me anywhere.

    Any help would be well appreciated.
  2. jcsd
  3. Oct 12, 2012 #2
    I don't know the answer as well, but I'll offer my view on this.

    The ideal gas law doesn't seem to be applicable here, as there will be a pressure and temperature increase as the gas enters the can.

    Also, is the 150cm3 the total empty space in the can? Because you mentioned there being a chemical precursor inside the can. It could affect the actual volume.

    Also, what is the flow rate of the nitrogen?

    CMIIW, but this is my take on the situation: as the pressure in the can will eventually even out with the pressure of the inlet, then it is important for us to know the flow rate of the nitrogen, so we can calculate the amount of nitrogen in the can after 20s, and thus the pressure.

    Alternatively, since you mentioned that this is an experiment, why not simply attach a pressure indicator?
    Last edited: Oct 12, 2012
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