Potassium chlorate is the most industrially important chlorate, or chlorate of potash, KClO3.
Potassium chlorate is a colourless crystalline substance that melts at 356°C and decomposes violently at about 400°C. It is a powerful oxidizing agent and is used in making explosives and matches; a mixture of potassium chlorate with phosphorus, sulphur, or any of numerous organic compounds (e.g., charcoal or sugar) explodes upon friction or percussion. When a chlorate is heated, oxygen is evolved, often explosively, and the chloride is formed; e.g., 2KClO3 => 2KCl+3O2. The reaction proceeds controllably at lower temperatures if a catalyst, e.g., manganese dioxide, is used; this provides a convenient source of oxygen. If the chlorate is heated carefully at a lower temperature so that no oxygen is given off, the perchlorate and chloride are formed; e.g., 4KClO3 => 3KClO4+KCl.