Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A question regarding electrolysis

Tags:
  1. Oct 2, 2016 #1
    Why does a different reaction occur at anode when electrode isn't inert and has the same metal ion as present in electrolyte?
    What will happen if the electrode isn't inert but is formed of a metal which is different than one present in electrolyte?

    For example, we know that in electrolysis of silver nitrate with silver electrodes yields a different reaction at anode. My question is why does such a different reaction occurs and what happens if we have a different, non-inert electrode, say for example copper (electrolysis of silver nitrate using copper electrodes) ?
     
    Last edited: Oct 2, 2016
  2. jcsd
  3. Oct 2, 2016 #2

    Borek

    User Avatar

    Staff: Mentor

    I have a feeling you have already answered your own question: reaction occurs because the electrode isn't inert.

    And you can't expect copper to react as if it was silver. It has to react the way copper does.
     
  4. Oct 2, 2016 #3
    Yeah so what will happen with the copper anode? Will a different reaction occur? If so what reaction?
     
  5. Oct 2, 2016 #4

    Borek

    User Avatar

    Staff: Mentor

    Non-inert anodes get oxidized. Why should the copper behave differently in this case?
     
  6. Oct 2, 2016 #5
    In electrolysis of AgNO3, when silver anode is used, instead of anion being liberated at anode (which happens in inert electrodes) we get a reaction which is very different.
    Instead of
    2O-+2e- -> O2
    We get
    Ag -> Ag+ + e-

    My question is why does the second reaction instead of the usual first reaction occurs, and which reaction will occur if the anode is copper?
     
  7. Oct 2, 2016 #6

    Borek

    User Avatar

    Staff: Mentor

    It depends on the redox systems present and on their formal potentials - the one with the lowest potential will react first. To predict what to expect you need to consult a data table (like this one).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: A question regarding electrolysis
Loading...