I find these problem fun and relatively easy, but this one is stumping me and I'd like some help. This is for some extra credit chemistry homework.
Target equation: FeO(s) + CO(g) -> Fe(s) + CO2(g)
3Fe2O3(s) + CO(g) -> 2Fe3O4(s) + CO2(g) ΔH=-47.0 kJ
Fe2O3(s) + 3CO(g) -> 2Fe(s) + 3CO2(g) ΔH=-25.0 kJ
Fe3O4(s) + CO(g) -> 3FeO(s) + CO2(g) ΔH=10.0 kJ
If you don't know what Hess's Law is but think you could help, what you have to do is arrange the 3 given equations, by multiplying them or flipping them or whatever algebra rules you want to use, so that when, combined the equations will cancel out to result in the target equation. Then you add up the ΔH values to find the ΔH of the target equation.