Doesn't there also have to be some notion of "atomic" (gcd?) reaction, otherwise you couldn't separate
2 H2 + 3 O2 + C <-> 2 H2O + CO2
into its constituent reactions
2 H2 + 2 O2 <-> 2 H2O + energy and C + O2 <-> CO2 + energy
Sounds like the border between alchemy and physical chemistry or chemical physics. There are all those laws of combining proportions and the atomic hypothesis etc. You could set up an equation with all 92 (or 105 or whatever) elements and try to sort out the resulting mess. In fact, adding energy to the equation is rather poetic; should it have a sign or even be quantified to indicate relative stability? High school chemistry should probably be left at simple mnemonics for analyzing simple and definitive reactions based on conservation of recognizable components. "Don't look a gift horse in the mouth!" -hvm