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Utlilizing Dalton's Law of Partial Pressures

  1. Jan 26, 2004 #1
    If a 2.0 L container of oxygen at 3 Atmospheres of pressure is poured into a 5.0 L container of Hydrogen at 3 atmospheres of pressure. What is the partial pressure of oxygen in new container? What is the new total pressure in the container?

    I'm not sure how to start this . . . if you could help me, I'd appreciate it.
  2. jcsd
  3. Jan 26, 2004 #2


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    Pressure is the only dependent variable in the gas law equation PV=nRT and is determined by temperature, volume, and the amount of gas. So, here is a practical way to do this problem.

    We know that a certain amount of oxygen, due to its energy, in a fixed volume exerts a certain pressure. If we are to increase the volume from 2.0L to 5.0L the pressure will decrease proportionally since we are only changing one variable. We decrease the pressure by 2.5. 3/2.5=1.2 atm. Add this to the pressure of hydrogen, 3 and you get 4.2 atm.
    Last edited: Jan 26, 2004
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