What is the formula for permanganate?

The formula for permanganate is MnO4^-. This anion includes one manganese (Mn) atom and four oxygen (O) atoms, and it carries a charge of -1.

Permanganate is well-known for its distinctive deep purple color in solution, which is primarily due to the manganese in a +7 oxidation state within the ion. This oxidation state arises from the electron configuration of manganese, allowing it to form a stable complex with four oxygen atoms.

The other formulas listed do not represent permanganate or are incorrectly structured for the species in question. For example, MnO4^2- indicates a di-ionic form that does not exist under normal conditions, MnO2 represents manganese dioxide, which is a different compound with manganese in a lower oxidation state, and Mn2O7 refers to manganese heptoxide, which is a different molecular species entirely. Thus, MnO4^- is the only correct representation of the permanganate ion.