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Mole and gas volume

  1. Dec 11, 2015 #1
    Dear PF Forum,

    1 mole O2 is roughly 32 grams?
    1 mole ozone is roughly 48 grams?
    1 mole CO2 is roughly 46 grams?
    Considering there are isotopes
    Do, at the same temperature and pressure, 1 mole CO2 and 1 mole O2 have the same volume?
    At the same pressure, does the volume of 1 mole O2 at 400K is 2/3 the volume of 1 mole O2 at 600K?

    I'm terribly sorry. I must have played truant at chemistry class:smile:

    I have a composter. There two holes on it. One at the upper side, one at the lower side. The composting process is the reverse of photosynthesis. That is.
    C6H12O6 + 6O2 -> 6CO2 + 6H2O
    So it seems that the composter is "inhaling" oxygen and "exhaling" CO2. If the volume of 1 mole O2 is the same as the volume of 1 mole CO2, then O2 must be at the higher part and can enter the upper hole easily. And CO2 will come out the lower hole.
  2. jcsd
  3. Dec 11, 2015 #2


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    Staff: Mentor

    A, B, and C are correct, but
    is not. That represents the combustion of sugar. For one, the composting material is not principally made of sugar. Also, composting is done by bacteria, so it is much more complicated than a simple chemical reaction. As you were told in another thread, there are for instance anaerobic bacteria that will decompose the organic matter in the absence of oxygen.

    That's a non-sequitur: even if all you had written was correct, I don't see how this would follow. In addition, the compost will be at a higher temperature than ambient air, so most of it will escape from the top hole.
  4. Dec 12, 2015 #3
    Thank you, thank you very much DrClaude.
    So, how do we introduce the oxygen to the composter? Do the composter gets its oxygen from the material not from the air? Do we have to open the hatch occasionally?
    Thanks for any reply. I'd like to do something for the environment. Perhaps if I know how to compost easily and correctly, I'll promote it to the people around me.
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