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Homework Help: Electrolysis of sodium sulphate

  1. Aug 12, 2018 at 11:44 AM #1
    1. The problem statement, all variables and given/known data
    I want to know what happens at the anode and why it happens during the electrolysis of sodium sulphate.
    2. The attempt at a solution
    Na+ and H+ move towards cathode, H+ is discharged due to Electrode potential values. What happens to the SO42- ions and how is O2 produced at anode?
     
  2. jcsd
  3. Aug 12, 2018 at 12:10 PM #2

    Borek

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    Staff: Mentor

    Hint: just like nothing happens to Na+, nothing happens to SO42-.

    What else is present in the solution?
     
  4. Aug 12, 2018 at 12:11 PM #3
    OH- is present, but how does OH- convert to O2?
     
  5. Aug 12, 2018 at 12:26 PM #4

    Borek

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    Try to guess the reaction, there are no many possibilities.
     
  6. Aug 12, 2018 at 12:32 PM #5
    I'm guessing OH- breaks into O2- and H+ and then O2- loses an electron
     
  7. Aug 12, 2018 at 12:44 PM #6

    Borek

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    Don't go for a mechanism, just write and balance the half reaction.
     
  8. Aug 12, 2018 at 12:55 PM #7
    O2- + e gives O2
     
  9. Aug 12, 2018 at 1:10 PM #8
  10. Aug 12, 2018 at 1:50 PM #9

    Borek

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    No, you have to start with what is present in the solution.
     
  11. Aug 13, 2018 at 7:19 AM #10
    3OH- + 3e gives O2 + H2O ??
    Its seems counter-intuitive to write either SO42- and OH- that is present directly as O2
     
  12. Aug 13, 2018 at 5:16 PM #11

    Borek

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    Can you balance it? If not, it can't be a right reaction equation.

    But in general you are on the right track - start with OH-, put O2 on the right side and see what you can do to balance the equation. You can use any ions and substances that are already present in the solution.
     
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