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Enthalpy of Reaction

  1. May 4, 2010 #1
    1. The problem statement, all variables and given/known data
    Given the following reactions

    Fe2O3 + 3CO ---> 2Fe + 3CO2 DeltaH = -28.0kJ
    3Fe + 4CO2 ---> 4CO + Fe3O4 DeltaH = 12.5kJ

    the enthalpy of the reactions of Fe2O3 with CO
    3Fe2O3 + CO ---> CO2 +2Fe3O4
    what is DeltaH for this equation? ________ kJ
    2. Relevant equations
    DeltaH = H(products) - H(reactants)

    3. The attempt at a solution
    I've tried to switch the equations around to isolate certain solutions but I've had no luck at all, I would really appreciate some help on this problem.
  2. jcsd
  3. May 4, 2010 #2

    Char. Limit

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    Well, start with something that's only in one equation and balance that. I'd recommend starting with balancing Fe2O3. Note: NOT Fe and O, but balance the compound. Treat the compound as an individual atom. Then do the same for a compound that's only in the other equation and balance that. Then work from there.
  4. May 4, 2010 #3
    Could you offer more assistance, I still don't really understand what to do.
  5. May 4, 2010 #4

    Char. Limit

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    Gold Member

    Well, first let me tell you that you don't need to switch around the equations at all. Simple multiplication will work in this case.

    That said, what do you need to multiply the first equation, with one Ferric Oxide, to get the third equation, with three Ferric Oxides?

    Same process with the other equation.
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