permanganate

Permanganate refers to the manganese oxoanions MnO4− and the salts derived from it, notably potassium permanganate (KMnO4). In MnO4−, manganese is in the +7 oxidation state; it is a powerful, widely used oxidizing agent.

In water, permanganate solutions are deeply purple. The exact color and products of reduction depend on pH: in acidic solutions MnO4− is reduced to Mn2+ (colorless to pale pink); in neutral to mildly basic media it tends to form MnO2 precipitate; in strongly basic solutions MnO4− can be reduced to manganate (MnO4^2−), which is green and unstable. KMnO4 and other permanganate salts are typically purple solids.

Production and sources: Commercial permanganates are produced industrially by oxidation of manganate solutions and are stabilized as salts such as KMnO4, NaMnO4, or broader manganate to permanganate processes. They are used as oxidizers in chemical synthesis and are also produced as disinfectants for water treatment.

Applications: In chemistry, permanganate is used for quantitative titration of reducing agents (permanganometry) and in organic oxidation reactions, including oxidation of alkenes, sulfides, and alcohols, and dehydrogenation under certain conditions. In industry and consumer products, KMnO4 acts as a disinfectant and sanitizer, a bleaching agent in textile and paper, and a stain remover in household products. It is also used to treat drinking water and wastewater.

Safety: Permanganate salts are strong oxidizers and may react violently with organic materials or reducing agents. Concentrated solutions can cause skin and eye burns, and ingestion is hazardous. They should be stored away from heat, moisture, and incompatible substances.