Death Of a Gummy Bear
The oxygen from the chlorate react with the Carbon in the gummy bear to form CO2
he reaction is exothermic so it continues to fuel the release of O2 from the chlorate to continue the reaction until the gummy is consumed.
Pharaoh's Serpent Reaction
Igniting mercury(II) Thiocyanate causes it to decompose into an insoluble brown mass that is primary carbon nitride C3N4. Mercury (II) sulfide and carbon disulfide are also produced.
CaC2 + 2 H2O → C2H2 + Ca(OH)2
This reaction is used in the commercial manufacture of acetylene and for carbide lamps, which are used by miners in some areas.