Potassium chlorate

Potassium chlorate is an inorganic compound with the chemical formula KClO3. In its pure state, it appears as a white solid. It is widely recognized as a very strong oxidizing agent. An oxidizer is a substance that provides oxygen to help other materials burn. This makes it the second most common chlorate used in industrial processes. Only sodium chlorate is used more frequently in industry than this compound.

Industrial production often uses a process called salt metathesis. In this reaction, sodium chlorate and potassium chloride react together. This process works because potassium chlorate has low solubility in water. Low solubility means it does not dissolve easily. As the reaction occurs, the potassium chlorate precipitates out of the liquid. Precipitation is when a solid forms and falls out of a solution. This constant formation helps drive the chemical reaction forward.

There are several other ways to create this chemical. Factories can use the electrolysis of sodium chloride to make the precursor sodium chlorate. Another method involves passing chlorine gas into a hot solution of caustic potash. Some processes also use the disproportionation of a sodium hypochlorite solution. This is followed by a metathesis reaction with potassium chloride. Each method relies on specific chemical changes to isolate the desired white solid.

Potassium chlorate has many different historical and practical uses. It was once a vital ingredient in early percussion caps for firearms. These caps acted as primers to start the firing process. Today, it is used as an oxidizer in smoke compositions for smoke grenades. It also serves roles in agriculture and science. In Finland, it was sold under the trade name Fegabit as a pesticide. It is also used to force longan trees into their blossoming stage. This helps the trees produce fruit even in warmer climates.

In science classrooms, the substance is used for famous demonstrations. One example is the "screaming jelly baby" or "screaming gummy bear" experiment. A teacher drops candy, such as Haribo or Trolli brands, into molten potassium chlorate. The reaction produces a loud screaming sound.

In a laboratory, scientists can use it to produce oxygen. If they heat the compound with a catalyst like manganese(IV) dioxide, it decomposes. This allows warm oxygen gas to be drawn off through a tube.

However, the chemical is extremely dangerous if handled incorrectly. It is a powerful oxidizer that reacts with many common materials. It can spontaneously react with sugar or even ordinary dust and lint. It is also very sensitive to certain chemicals and physical forces. Mixtures containing sulfur, phosphorus, or lactose are sensitive to shock and friction. This means hitting or rubbing them can cause a reaction. Contact with sulfuric acid can cause a mixture to ignite spontaneously.

Because of its reactive nature, it has been used in violent ways. In Afghanistan, militant groups used it to make improvised explosive devices (IEDs). This happened after the availability of ammonium nitrate fertilizer was reduced. By 2013, 60% of IEDs in Afghanistan used potassium chlorate as a primary ingredient. It was also the main ingredient in the car bomb used during the 2002 Bali bombings. That event resulted in the deaths of 202 people.