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    I'm so confused about what we're supposed to know about hydrogen fuel cells. I have two textbooks and one of them quotes the half equations for an alkaline electrolyte:
    H2 + 2 OH- => 2H2O + 2e-
    1/2 O2 + H2O + 2e- => 2 OH-
    And one gives the half equations for an acid electrolyte:
    H2 => 2 H+ +2 e-
    1/2 O2 +2 H + 2 e- => H2O
    To me the equations for an acid electrolyte make much more sense in terms of what is actually going on; I don't get the ones with an alkaline electrode at all. The spec just says 'Explain the changes that take place at each electrode in a hydrogen-oxygen fuel cell' so I'm so confused about which ones to learn as the two textbooks conflict. If anyone can help thank you so much in advance!
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    Sorry you've not had any responses about this. Are you sure you've posted in the right place? Here's a link to our subject forum which should help get you more responses if you post there.

    You can also find the Exam Thread list for A-levels here and GCSE here. :dumbells:


    Just quoting in Puddles the Monkey so she can move the thread if needed
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    (Original post by Puddles the Monkey)
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    This explains it pretty well, https://youtu.be/xDBNJpcoGrk
    If you don't find it go to machemguy on YouTube and go to his playlist go to unit f325 energy which will include a video on fuel cells.
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    It is easy to convert any acid half equation into an alkaline one:

    Add as many OH- to both sides are there are H+. Convert the H+ and OH- to water. Cancel the waters from both sides (as required).

    e.g. MnO4- + 8H+ + 5e- -> Mn2+ + 4H2O
    becomes
    MnO4- + 8H+ +8OH- + 5e- -> Mn2+ + 4H2O + 8OH-
    becomes
    MnO4- + 8H2O + 5e- -> Mn2+ + 4H2O + 8OH-
    becomes
    MnO4- + 4H2O + 5e- -> Mn2+ + 8OH-

    Applying that to fuel cells:

    H2 -> 2H+ + 2e-
    becomes
    H2 + 2OH- -> 2H2O + 2e-

    O2 + 4H+ + 4e- -> 2H2O
    becomes
    O2 + 2H2O + 4e- -> 4OH-
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    (Original post by Pigster)
    It is easy to convert any acid half equation into an alkaline one:

    Add as many OH- to both sides are there are H+. Convert the H+ and OH- to water. Cancel the waters from both sides (as required).
    Thank you so much for this!
 
 
 
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