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

Homework Help: Contradicting predictions

  1. Mar 23, 2005 #1
    Ok this is about electrolysis of sodium Sulphate

    I believe the formula is

    Na2SO4 + 2H2O ----> 2NaOH + H2SO4

    During the lab, the indicator at the cathode turned basic and the anode indicated acidic.

    Explaining this using electric potentials:
    Na + e = Na E = -2.71 V
    H2O + e = ½ H2 + OH- E = -0.83 V
    S2O8 + 2e = 2SO4 E = 2.05 V
    ½ O2 + 2H = H2O E = 1.23 V

    water = 1.23 – (-0.83) = 2.06 V
    sodiumSulphate = 2.05 – (-2.71) = 4.76 V

    The battery used were 3V

    I have no idea how this results in the original reaction formula above. Can someone englighten me? :smile:
     
    Last edited: Mar 23, 2005
  2. jcsd
  3. Mar 23, 2005 #2
    ummm i think i solved the problem, but thanks anyway.

    Dunno how to delete the thread :cry:
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook