KMnO4 is an inorganic compound that is used as an oxidizing agent in chemical synthesis. It is also a good disinfectant and is a useful tool in water treatment.
In an alkaline solution, it reduces spontaneously to form manganese dioxide (MnO2) and releases oxygen gas. KMnO4 is also a good oxidizing agent and attacks many organic substances. It can be used to oxidize metals such as iron and copper. It can also oxidize other inorganic chemicals such as iodides, bromates, and carbonates. KMnO4 is a strong oxidizing agent and has a high melting point. It is an odourless solid and exists as dark purple crystals. When dissolved in water it forms a pink to purple solution. The colour of the solution fades when the reaction is complete. This is because the KMnO4 ions have been used up in the reaction and is known as a self indicator. This property of KMnO4 makes it very useful as an oxidizing agent in laboratory experiments.
It is used as an antidote for barbiturates and chloral hydrate poisoning. A solution of 1:5000 of potassium permanganate in water is used as a stomach wash to oxidize the proteins that have been absorbed from ingested drugs and prevent their absorption. It is also used as a stain in biology to highlight cells and tissues.
Concentrated KMnO4 can cause eye and skin irritation. Long term exposure may damage the eyes permanently. Inhalation of concentrated KMnO4 can lead to coughing, shortness of breath and pulmonary oedema (buildup of fluid in the lungs). Potassium permanganate is toxic if swallowed, causing brown discolouration of the gums & mucous membranes of the mouth & throat; nausea, vomiting & diarrhea.