True enough, but still, you've gone and quoted Hess's Law here as well, but still -- in practical terms, how will the "energy" be put into the reaction? Do you mean simply thermal energy?
Like for K2O(s)->2K+(g) +O2-(g), C(s)->C(g) energy is absorbed and in O2-(g)+C(g)->CO(g)+2e, 2K+(g)+2e->2K(g) and K(g)->K(s) energy is being released?
But actually I'm not too sure where the energy goes.. Do some of these reaction have an activation energy? Because in boiling/solidification I don't think there's an activation energy right?
And for my O2-(g)+C(g)->CO(g)+2e it should be simplified to O2-(g)->O+2e and C+O->CO so I'm not sure if these 2 reactions here have an activation energy too.
I'm thinking this step by step process should be split into the bond breaking part of the reaction (which adds up to activation energy) and the bond forming part of the reaction (which adds up to the reverse activation energy).
So I would guess that energy is being put in to the bond breaking components of the reaction like this: http://postimg.org/image/6ufkwqa9d/
That's why I don't see why I can't use carbon for these reactions. Didn't carbon only increase the activation energy (cos i have to turn it into a gas) and also give out some energy (when it reformed CO). So thinking about this now if i were to just decompose 2K2O->4K+O2, then my activation energy would be smaller as now bond breaking or activation energy would just be: 2K2O(s)->4K+(g)+2O2-(g), 2O2-(g)->2O(g)+4e and bond forming would be: 4K+(g)+4e->4K(g), 4K(g)->4K(s) and 2O(g)->O2(g). So in this reaction won't the activation energy be smaller?
Hmm this is pretty confusing now.. I don't see the need for carbon besides it giving out energy with a reaction with an oxygen atom. Could you explain my misconceptions here? Thanks