Balancing redox reactions occurring in acidic solutions

  1. 1. The problem statement, all variables and given/known data
    Balance the following redox reactions occurring in an acidic solution.


    2. Relevant equations
    PbO2(s)+I-(aq)---->Pb2+(aq)+I2(s)


    3. The attempt at a solution
    1.) half reactions:
    a.) reduction: I-(aq)----->I2(s)
    b.) oxidation: PbO2(s)------>Pb2+(aq)
    2.) balance Oxygens and Hydrogens
    PbO2+4H+------>Pb2++2H2O
    3.) add electrons to balance equations
    a.)PbO2+4H++4e---->Pb+2+2H2O
    b.) 4I--->4I2+4e-
    4.) cancel out the electrons and combine the half reactions
    PbO2+4H++4I--->Pb2++4I2+2H2O
     
  2. jcsd
  3. Borek

    Staff: Mentor

    Nope.
     
    Last edited by a moderator: Aug 13, 2013
  4. I don't understand how to insert the number of electrons on both sides to balance the equations and cancel out the electrons.
     
  5. Borek

    Staff: Mentor

    Balance atoms first, then use electrons to balance charge in half reaction. As long as charge on both sides is different, equation is not balanced.
     
    Last edited by a moderator: Aug 13, 2013
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