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Homework Help: Estimating the expected yield of a chemical reaction

  1. Jun 26, 2008 #1
    Scenario: Suppose that a pump creates a partial vacuum, which is used to input air (gas) from the environment into a long tube. At a certain point within this tube, diatomic hydrogen and oxygen (gases) are also inputted into the tube. The tube outputs back into the environment. I have provided a diagram that illustrates this.

    Goal: What is a good theoretical procedure for estimating what portion of the added inputs, hydrogen and oxygen, is transformed into water before being outputted to the environment?

    Here are my thoughts on what factors to consider:
    1. The dimensions of the tube; length, since that sets the time limit in which the gases must react, and diameter, since this determines what region of space the gases are permitted to move in.
    2. The amounts of input substances; obvious.
    3. Temperature; affects the kinetic energy of the molecules and the rate of reactions.
    4. Pressure gradient; I expect that, in general, this would cause a unidirectional flow of the gas molecules and change in the kinetic energy of the molecules, maybe even affecting the rate of the reaction (?)

    Any advice on the mathematical analysis or additional concepts to consider would be greatly appreciated. Thanks for your time.

    Attached Files:

  2. jcsd
  3. Jun 26, 2008 #2


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    Staff: Mentor

    Can't see attachement yet, but from the description it sounds like a continuous flow reactor. I suppose any good chemical engineering book will have a section describing how to solve the problem. Not being engineer myself (heck, I am not even a chemist) I can't point you to any exact title.
  4. Jun 28, 2008 #3


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    Science Advisor
    Homework Helper

    The Arrhenius equation should be helpful for this application so you should demonstrate the application of this equation to your problem. You ultimately need to consider the rate of the conversion and the time that the hydrogen and oxygen gases spend within the tube; the latter is an independent variable.
  5. Jul 3, 2008 #4
    Problem solved.
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