Barium chlorate in some sodium contamination, which is undesirable for pyrotechnic purposes, where the strong yellow of sodium can easily overpower the green of barium. Sodium-free barium chlorate can be produced directly through electrolysis: It can also be produced by the reaction of barium carbonate with boiling ammonium chlorate solution: The reaction initially produces barium chlorate and ammonium carbonate; boiling the solution decomposes the ammonium carbonate and drives off the resulting ammonia and carbon dioxide, leaving only barium chlorate in solution. When exposed to heat, barium chlorate alone will decompose to barium chloride and oxygen: Barium chlorate is used to produce chloric
Chlorate were once widely used in pyrotechnics for this reason, though their use has fallen due to their instability. Most pyrotechnic applications that formerly used chlorates now use the more stable perchlorates instead. The chlorate ion cannot be satisfactorily represented by just one Lewis structure, since all the Cl–O bonds are the same length (1.49 Å in potassium chlorate), and the chlorine atom is hypervalent. Instead, it is often thought of as a hybrid of multiple resonance structures: Metal chlorates can be prepared by adding chlorine to hot metal hydroxides like KOH: In this reaction, chlorine undergoes disproportionation, both reduction and