@lucifargundam I know of no such site, not the way you want it, and im not sure such thing could really exist. Bear in mind, however, I'm far from an expert in chemistry, at best its a hobby for me..

So the issue I see here is that "decomposition" just means a chemical breaks down into constuent parts in some way and tends to imply there is no rearrangement of its parts with some reaction with another chemical. This is all fine and good however the results of decomposition depend greatly on the circumstances.

For example consider there are really several routes to decomposition: catalytic, UV break down, heat, electrolysis. Each one of these routes will usually produce entierly different decomposition products. Even then within a specific route the decomposition product can be almost anything as you tweak parameters, the temperature, frequency of UV, the catalyst chosen, as well as the pressure and even concentration of the reaction vessel will all have a huge effect. If any solvents are involved to facilitate the reaction (as would be the case with catalytic reactions usually) would also have a huge effect.

Take a really simple example, hydrogen peroxide which is just four atoms, two hydrogen, two oxygen. heat it up a little bit or use a catalyst and youll wind up with water and oxygen. Heat it up a great deal (as would also be the case with water alone) and it will decompose down to H2 and O2 separately (which is why if firemen try to put out extremely hot fires like magnesium fires with water it will cause explosions). Heat it up even more and you get elemental H and O separately rather than their diatomic form.

Now in the case of H2O2 there really arent too many break down options simply because you only have 2 different atoms so they can only combine in a limited number of ways. But we have literally just covered every single combination of H and O that can exist by describing all the decomposition routes of H2O2 via heating alone. Doable for such a simple molecule but for more complex molecules describing every route exhaustively becomes impossible.

The best you could hope for from such a database/site would be for it to describe a very limited set of common decompositions. For example it might just limit decomposition to various temperatures and what the most predominate results are and leave off the small % decomposition by products. But the cut off would be arbitrary in both the choice of temperature and the choice of % needed to list it as a decomposition.

For example pure water at room temperature will instantly "decompose" (we dont call this decomposition really) into H+ and OH- ions in very small concentrations. Most of the time its so small we ignore this even though some H+ ions will randomly neutralize and form H2, but the rate and concentration at which that happens is so small as to be pointless to think of it as existing at all. So in any reasonable % cut off we would lnot describe that as a natural decomposition at room temperature. But none the less it is there.

So yea long story short I dont think you will find what you are after. Best you might fine is sources like wikipedia that describe some very common decompositions and is no where near comprehensive.

#Chemistry #STEM #Science @trinsec