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| Names | |
|---|---|
Other names
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| Identifiers | |
3D model (JSmol) | |
| ChEMBL | |
| ChemSpider |
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| ECHA InfoCard | 100.021.173 |
| EC Number |
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| RTECS number |
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| UNII | |
| UN number | 1485 |
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| Properties | |
| KClO3 | |
| Molar mass | 122.55 g·mol−1 |
| Appearance | white crystals or powder |
| Density | 2.32 g/cm3 |
| Melting point | 356 °C (673 °F; 629 K) |
| Boiling point | 400 °C (752 °F; 673 K) decomposes[1] |
| |
| Solubility | negligible inacetone and liquidammonia[1] |
| Solubility inglycerol | 1 g/100g (20 °C (68 °F; 293 K))[1] |
| −43.8×10−6 cm3/mol | |
Refractive index (nD) | 1.40835 |
| Structure | |
| monoclinic | |
| Thermochemistry[1] | |
| −391.2 J/(mol·K) | |
Std molar entropy(S⦵298) | 142.97 J/(mol·K)[3] |
Std enthalpy of formation(ΔfH⦵298) | −391.2 kJ/mol[3] |
Gibbs free energy(ΔfG⦵) | −289.9 kJ/mol |
| Hazards | |
| GHS labelling:[4] | |
  | |
| Danger | |
| H271,H301,H401[4] | |
| P210,P220,P221,P264,P270,P273,P280,P283,P301+P310+P330,P306+P360,P370+P378,P371+P380+P375,P405,P501[4] | |
| NFPA 704 (fire diamond) | |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose) | 100 mg/kg (oral, rat)[5] |
LC50 (median concentration) | >5.1 mg/L[5] |
| Related compounds | |
Otheranions | |
Othercations | |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Potassium chlorate is theinorganic compound with the molecular formula KClO3. In its pure form, it is a white solid. Aftersodium chlorate, it is the second most commonchlorate in industrial use. It is a strongoxidizing agent and its most important application is in safetymatches.[6]
On the industrial scale, potassium chlorate is produced by thesalt metathesis reaction ofsodium chlorate andpotassium chloride:
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 byelectrolysis ofsodium chloride, common table salt.[6]
The direct electrolysis ofKCl in aqueous solution is also used sometimes, in which elemental chlorine formed at theanode reacts with KOHin situ. The lowsolubility ofKClO3 in water causes the salt to conveniently isolate itself from thereaction mixture by simply precipitating out of solution.
Potassium chlorate can be produced in small amounts bydisproportionation in asodium hypochlorite solution followed bymetathesis reaction with potassium chloride:[citation needed]
It can also be produced by passing chlorine gas into a hot solution of caustic potash:[7][page needed]
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Potassium chlorate was one key ingredient in earlyfirearmspercussion caps (primers).[8]
Another application of potassium chlorate is as the oxidizer insmoke compositions such as those used insmoke grenades.[9]
Potassium chlorate readily decomposes if heated while in contact with acatalyst, typicallymanganese(IV) dioxide (MnO2). Thus, it may be simply placed in a test tube and heated over a burner. If the test tube is equipped with a one-holed stopper and hose, warm oxygen can be drawn off. The reaction is as follows:
Heating it in the absence of a catalyst converts it intopotassium perchlorate:[7][page needed]
With further heating, potassium perchlorate decomposes topotassium chloride and oxygen:
The safe performance of this reaction requires very pure reagents and careful temperature control. Molten potassium chlorate is an extremely powerful oxidizer and spontaneously reacts with many common materials such as sugar. Explosions have resulted from liquid chlorates spattering into the latex or PVC tubes of oxygen generators and from contact between chlorates and hydrocarbon sealing greases. Impurities in potassium chlorate itself can also cause problems.
Potassium chlorate reacts with sulfuric acid to form highly reactivechlorine dioxide, potassium sulfate, oxygen, and water:[10]
Chlorine dioxide, combined with oxygen gas (and any remaining potassium chlorate) is sufficiently reactive that it spontaneously ignites if combustible material (sugar, paper, etc.) is present.[citation needed]
In schools, molten potassium chlorate is used inscreaming jelly babies,Gummy bear,Haribo, andTrolli candy demonstration where the candy is dropped into the molten salt.[11]
Potassium chlorate is used also as apesticide. In Finland it was sold under trade name Fegabit.[citation needed]
Potassium chlorate is used to force the blossoming stage of thelongan tree, causing it to produce fruit in warmer climates.[12][13]
Militant groups inAfghanistan also use potassium chlorate extensively as a key component in the production ofimprovised explosive devices (IEDs). When significant effort was made to reduce the availability ofammonium nitrate fertilizer in Afghanistan, IED makers started using potassium chlorate as a cheap and effective alternative. In 2013, 60% of IEDs in Afghanistan used potassium chlorate, making it the most common ingredient used in IEDs.[14]Potassium chlorate was also the main ingredient in the car bomb used in the2002 Bali bombings that killed 202 people.[15]
Potassium chlorate is a very powerful oxidizer. It reacts vigorously, and in some cases spontaneously ignites or explodes, when mixed with manycombustible materials. It burns vigorously in combination with virtually any combustible material, even those normally only slightly flammable (including ordinary dust and lint). Mixtures of potassium chlorate and a fuel can ignite on contact with sulfuric acid. Mixtures of potassium chlorate with lactose,[16] sulfur,[16]: 18–5 sulfides such asantimony(III) sulfide,[16]: 18–5 or phosphorus are extremely shock and friction sensitive.
