Color source
The characteristic intense color is associated with MnO₄⁻.
Electronic transitions in the permanganate ion absorb strongly in the visible region.
Ionic solid · permanganate salt
Potassium permanganate
KMnO₄
Potassium permanganate is KMnO₄, an ionic solid composed of K⁺ and MnO₄⁻. The permanganate ion has a tetrahedral manganese–oxygen framework and manganese in oxidation state +7.
Safety-relevant chemistry: permanganate is a strong oxidizing species. This page explains structure and redox concepts, not reactive formulations.
Essentials
KMnO₄ is one K⁺ ion for one MnO₄⁻ ion.
The +1 and −1 charges balance in a 1:1 formula unit. Potassium is not covalently inserted into the MnO₄ framework.
Detail
Permanganate is tetrahedral with four symmetry-related oxygen positions.
The ion is best represented through a delocalized Mn–O bonding picture rather than one oxygen being permanently singled out by a localized Lewis double bond.
Oxidation state
Manganese is assigned +7 in MnO₄⁻.
That high oxidation state is central to permanganate's oxidizing behavior.
Understand
In water, the ionic lattice separates into K⁺ and MnO₄⁻.
The permanganate ion remains intact as a solvated polyatomic ion. Its redox products depend strongly on chemical environment, especially acidity and reaction partner.
Redox context
One formula does not predict one universal reduction product.
Permanganate can follow different redox pathways under different conditions, so reaction context must be specified.
Reference identifiers
Names and identifiers that pin down the chemical identity.
| Formula | KMnO₄ |
|---|---|
| CAS Registry Number | 7722-64-7 |
| Ions | K⁺ and MnO₄⁻ |
Advanced
Push past the first model without losing the simple picture.
Is KMnO₄ a molecule?
No. The solid is ionic and is represented by formula units.
Why is Mn assigned +7?
Four oxygens at −2 total −8; the ion charge is −1, so manganese must be +7 in oxidation-state bookkeeping.
Does dissolution reduce permanganate?
No. Dissolution can occur without changing manganese oxidation state; redox requires electron transfer.
Constituent elements