Potassium chlorate

Potassium chlorate is a compound containing potassium, chlorine and oxygen, with the molecular formula KClO3. In its pure form, it is a white crystalline substance. After sodium chlorate, it is the second most common chlorate in industrial use. It is a strong oxidizing agent and its most important application is in safety matches. In other applications it is mostly obsolete and has been replaced by safer alternatives in recent decades. It has been used in fireworks, propellants and explosives, to prepare oxygen, both in the lab and in chemical oxygen generators, as a disinfectant, for example in medical mouthwashes, in agriculture as an herbicide. On the industrial scale, potassium chlorate is produced by the salt metathesis reaction of sodium chlorate and potassium chloride: NaClO3 + KCl → NaCl + KClO3 The reaction is driven by the low solubility of potassium chlorate in water. The equilibrium of the reaction is shifted to the right hand side by the continuous precipitation of the product (Le Chatelier's Principle). The precursor sodium chlorate is produced industrially in very large quantities by electrolysis of sodium chloride, common table salt. The direct electrolysis of KCl in aqueous solution is also used sometimes, in which elemental chlorine formed at the anode reacts with KOH in situ. The low solubility of KClO3 in water causes the salt to conveniently isolate itself from the reaction mixture by simply precipitating out of solution. Potassium chlorate can be produced in small amounts by disproportionation in a sodium hypochlorite solution followed by metathesis reaction with potassium chloride: 3 NaOCl(aq) → 2 NaCl(s) + NaClO3(aq) KCl(aq) + NaClO3(aq) → NaCl(aq) + KClO3(s) It can also be produced by passing chlorine gas into a hot solution of caustic potash: 3 Cl2(g) + 6 KOH(aq) → KClO3(aq) + 5 KCl(aq) + 3 H2O(l) Potassium chlorate was one key ingredient in early firearms percussion caps (primers). It continues in that application, where not supplanted by potassium perchlorate.