Enthalpy of Reaction: Fe2O3 + CO --> CO2 + 2Fe3O4

[Faiien]

Homework Statement

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

Homework Equations

DeltaH = H(products) - H(reactants)

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.

 

[Char. Limit]

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.

 

[Faiien]

Could you offer more assistance, I still don't really understand what to do.

 

[Char. Limit]

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.