Potassium nitrate has an orthorhombic crystal structure at room temperature, which transforms to a trigonal system at 129 °C. Upon heating to temperatures above 560 °C, it decomposes into potassium nitrite, generating oxygen:
- 2 KNO3 → 2 KNO2 + O2
Potassium nitrate is moderately soluble in water, but its solubility increases with temperature (see infobox). The aqueous solution is almost neutral, exhibiting pH 6.2 at 14 °C for a 10% solution of commercial powder. It is not very hygroscopic, absorbing about 0.03% water in 80%relative humidity over 50 days. It is insoluble in alcohol and is not poisonous; it can react explosively with reducing agents, but it is not explosive on its own.[4]During the 19th century and until around World War I, potassium nitrate was produced on an industrial scale by the Birkeland–Eyde process. Today practically all nitrates are produced from the oxidation of ammonia made by the Haber process.
they got to stop us from playing smoke..;AntiFRU