Ammonium permanganate is the chemical compound NH₄MnO₄, or NH₃· HMnO₄. It is a water soluble, violet-brown or dark purple salt.

Preparation

Ammonium permanganate was first prepared by Eilhard Mitscherlich in 1824 by reaction of silver permanganate with equal molar amount of ammonium chloride, filtering the silver chloride and evaporating the water. :AgMnO₄ + NH₄Cl → AgCl + NH₄MnO₄ It can also be prepared in a similar way from

barium permanganate Barium permanganate is a chemical compound, with the formula Ba(MnO4)2. It forms violet to brown crystals that are sparingly soluble in water. Preparation Barium permanganate may be produced by disproportionation of barium manganate in a mildly a ...

and ammonium sulfate. :Ba(MnO₄)₂ + (NH₄)₂SO₄ → BaSO₄ + 2 NH₄MnO₄

Properties

Ammonium permanganate is a strong oxidizer, owing to its permanganate anion, and it is a moderately strong

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

, owing to the combination of oxidizer permanganate anion and reducing

ammonium The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary a ...

cation. Dry ammonium permanganate can detonate by heat, shock, or friction, and it may explode at temperatures above 140 °F (60 °C). Ammonium permanganate decomposes explosively to

manganese dioxide Manganese dioxide is the inorganic compound with the formula . This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for is for dry-cell ...

, nitrogen, and water: :2 NH₄MnO₄ → 2 MnO₂ + N₂ + 4 H₂O Ammonium permanganate decomposes slowly in storage even at normal temperatures. A sample stored for 3 months was only 96% pure, after 6 months it assumed color of iodine and had strong smell of nitrogen oxides. It emits toxic fumes when decomposed by heat. Quaternary ammonium permanganate compounds can be prepared, such as tetrabutylammonium permanganate and benzyltriethylammonium permanganate.

References

Ammonium compounds Permanganates Oxidizing agents Pyrotechnic oxidizers Explosive chemicals {{inorganic-compound-stub