Products
Potassium nitrate is available as open goods in pharmacies and drugstores.
Structure and properties
Potassium nitrate (KNO3, Mr = 101.1 g/mol) exists as a white crystalline powder or as colorless crystals. It is slightly soluble in water at room temperature and very soluble in boiling water. Potassium nitrate is odorless, has a cooling salty taste and is somewhat bitter. It should be kept tightly closed and dry.
Effects
Potassium nitrate has oxidizing properties. It releases oxygen when heated, thus improving combustion and can cause explosions:
- 2 KNO3 (potassium nitrate) 2 KNO2 (potassium nitrite) + O2 (oxygen)
See also under redox reactions.
Areas of application
In pharmacy:
- Potassium nitrate is contained in toothpaste and tooth rinses, which are used to treat tooth neck hypersensitivity.
- Used in the preparation of cold mixtures.
Earlier applications:
- For the preparation of incense powders, asthma powder (eg Pulvis Stramonii compositus) and saltpetre paper (Charta nitrata). Potassium nitrate improves the burning.
- As a diuretic (obsolete due to side effects).
Used in the manufacture of fireworks, explosives and gunpowder:
- Potassium nitrate is used to make black powder (+ charcoal powder + sulfur), smoke bombs (+ sugar) or for fuses (+ blotting paper). Be careful when dispensing to adolescents at the pharmacy or drugstore! We recommend that dispensing to adolescents is generally refused. Potassium nitrate is one of the precursors for explosives.
For food:
- For preserving / curing meat (= E 252).
Various technical applications, for example, as a fertilizer.