Potassium bicarbonate dry chemical fire extinguishers, as the principal component of the Purple-K dry chemical, and in some applications of condensed aerosol fire suppression. It is the only dry chemical fire suppression agent recognized by the U.S. National Fire Protection Association for firefighting at airport crash rescue sites. It is about twice as effective in fire suppression as sodium bicarbonate. Potassium bicarbonate is an effective fungicide against powdery mildew and apple scab, allowed for use in organic farming. Potassium bicarbonate has widespread use in crops, especially for neutralizing acidic soil. The word "saleratus", from Latin "sal æratus" meaning "aerated salt", was widely
Potassium oxide Potassium oxide Potassium oxide (KO) is an ionic compound of potassium and oxygen. This pale yellow solid, the simplest oxide of potassium, is a rarely encountered, highly reactive compound. Some materials of commerce, such as fertilizers and cements, are assayed assuming the percent composition that would be equivalent to the chemical compound mixture KO. Potassium oxide is produced from the reaction of oxygen and potassium; this reaction affords potassium oxide, KO. Treatment of the peroxide with potassium produces the oxide: Alternatively and more conveniently, KO is synthesized by heating potassium nitrate with metallic potassium: Other possibility is to heat potassium