Which species is permanganate?

Which species is permanganate?

• A. MnO3-
• B. MnO4-
• C. MnO2
• D. MnO4^2-

Answer: (B)

Permanganate refers to the MnO4− ion, where manganese is in the +7 oxidation state. In MnO4−, each oxygen is −2, giving a total of −8 from the four oxygens. To achieve the overall −1 charge, manganese must be +7 (since +7 + (−8) = −1). This +7 oxidation state is the highest among the manganese oxyanions listed, which is what defines permanganate. The other species correspond to lower oxidation states for manganese: MnO2 has Mn in +4, MnO3− has Mn in +5, and MnO4^2− has Mn in +6. Thus MnO4− is the permanganate.

Permanganate refers to the MnO4− ion, where manganese is in the +7 oxidation state. In MnO4−, each oxygen is −2, giving a total of −8 from the four oxygens. To achieve the overall −1 charge, manganese must be +7 (since +7 + (−8) = −1). This +7 oxidation state is the highest among the manganese oxyanions listed, which is what defines permanganate. The other species correspond to lower oxidation states for manganese: MnO2 has Mn in +4, MnO3− has Mn in +5, and MnO4^2− has Mn in +6. Thus MnO4− is the permanganate.