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Homework Help: Ionic/redox reactions need checking

  1. May 7, 2012 #1
    ionic/redox reactions need checking :)

    Hi again, I had a number of questions that im not quite sure about. Ive asked peers, although they seem confused too.
    1. When you have NaOH + Fe2O3. xH2O would the sodium displace the iron, from rust, to form NaO3+ H2O?
    2. Oxidisation-reduction reaction for iron rusting. Heres what I got, although im not too sure its correct:
    4 Fe(s) + 6 H2O(l) + 3 O2(g) = 4 Fe3+(aq) + 12 OH-(aq)
    Fe2+(aq) + 2OH-(aq) = Fe(OH)2(s)
    Fe(OH)2(s) + O2(g) = Fe(OH)3(s)
    Fe(OH)3(s) = (dehydrates) Fe2O3.xH2O(s) + H2O(l)

    And again: iron reacting with citric acid
    Fe¬(s) = Fe2+ (s) + 2e-
    C6H8O7 (aq) = C6H6O72- (aq) + 2 H+(g)
    Fe2+ (s) + C6H6O72- (aq) = FeC6H6O7 (s)
    2e- + 2 H+ = H2 (g)

    And: iron reacting with acetic acid
    Fe(s) = Fe2+ (aq) + 2e-
    2 CH3COOH(aq) = (CH3COO)2- (aq) + 2 H+(g)
    Fe2+ (s) + (CH3COO)-2 (aq) = Fe (CH3COO)2 (s)
    2e- + H+2 = H2

    3. And: copper reacting with acetic acid
    Cu(s) = Cu2+ (s) +2e-
    2 CH3COOH(aq) = (CH3COO)2- (aq) + 2 H+(g)
    Cu2+ (s) + (CH3COO)-2 (aq) = Cu (CH3COO)2 (s)
    2e- + 2 H+ = H2 (g)
    4. And copper reacting with citric acid:
    Cu(s) = Cu2+ (s) +2e-
    2 C6H8O7 (aq) = (C6H5O7)2-(aq) + 6 H+(g)
    3 Cu2+ (s) + 2 (C6H5O7)2-(aq) = Cu3(C6H5O7)2 (s)
    2e- + 2 H+ = H2 (g)
    5. and if i added salt crystals to water, and put an iron nail in it, would the salt draw away the ions from the iron in the water? (thus slowing down the corrosion of iron)

    Sorry for all the trouble!
    Last edited by a moderator: May 7, 2012
  2. jcsd
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