Which compound, KMnO₄, is known for its deep purple color?

Potassium permanganate is the compound with the formula KMnO₄ that is known for its deep purple color.

It is an ionic compound made of potassium ions and permanganate ions. The permanganate ion contains manganese in the +7 oxidation state, and its electronic structure gives concentrated crystals their striking dark purple appearance. In dilute solution, the color becomes pink or pale purple.

Potassium permanganate is a powerful oxidizing agent. Historically and industrially, it has been used in water treatment, analytical chemistry, disinfecting applications, and some organic reactions. Its strong oxidizing behavior means it should be handled carefully and kept away from easily oxidized materials.

Potassium dichromate is another brightly colored oxidizing compound, but it is orange and has the formula K₂Cr₂O₇. Copper sulfate is commonly blue, while sodium permanganate is a different permanganate salt with sodium rather than potassium.