KNO3, or potassium nitrate, is soluble in water. Its solubility rises from 133 grams per liter at 0 degrees Celsius to 2,460 grams per liter at 100 degrees Celsius. Potassium nitrate is also soluble in glycerol and ammonia but only slightly soluble in alcohol.
Potassium nitrate is a key component in the manufacture of black powder, a form of gunpowder that is used in making rocket motors. It is also used in manufacturing smoke bombs, cigarettes, ceramics, glass and fertilizer. In medicine, it was once used to treat high blood pressure and asthma and is still used in toothpastes for sensitive teeth. Potassium nitrate is used in food preservation and preparation but can cause skin and eye irritations and is toxic when ingested or inhaled.