Permanganate

"MnO4" redirects here. For the manganate ion MnO2−4, see Manganate. For the hypomanganate ion MnO3−4, see Hypomanganate.
Permanganate
Lewis structure of the manganate(VII) anion
Names
Systematic IUPAC name
Permanganate
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
UNII
  • InChI=1S/Mn.4O/q;;;;-1
    Key: NPDODHDPVPPRDJ-UHFFFAOYSA-N
  • [O-] [Mn](=O)(=O)=O
Properties
MnO−
4
Molar mass 118.934 g·mol−1
Conjugate acid Permanganic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

A permanganate (/pərˈmæŋɡəneɪt, pɜːr-/)[1] is a chemical compound with the manganate(VII) ion, MnO−
4, the conjugate base of permanganic acid. Because the manganese atom has a +7 oxidation state, the permanganate(VII) ion is a strong oxidising agent. The ion is a transition metal ion with a tetrahedral structure.[2] Permanganate solutions are purple in colour and are stable in neutral or slightly alkaline media. The exact chemical reaction depends on the carbon-containing reactants present and the oxidant used. For example, trichloroethane (C2H3Cl3) is oxidised by permanganate ions to form carbon dioxide (CO2), manganese dioxide (MnO2), hydrogen ions (H+), and chloride ions (Cl−).[3]

8MnO−
4 + 3C
2H
3Cl
3 → 6CO
2 + 8MnO
2 + H+
 + 4H
2O + 9Cl−

In an acidic solution, permanganate(VII) is reduced to the pale pink manganese(II) (Mn2+) with an oxidation state of +2.

8 H+
 + MnO−
4 + 5 e− → Mn2+ + 4 H2O

In a strongly basic or alkaline solution, permanganate(VII) is reduced to the green manganate ion, MnO2−
4 with an oxidation state of +6.

MnO−
4 + e− → MnO2−
4

In a neutral solution, however, it gets reduced to the brown manganese dioxide MnO2 with an oxidation state of +4.

2 H2O + MnO−
4 + 3 e− → MnO2 + 4 OH−
  1. ^ "permanganate". Merriam-Webster.com Dictionary. Merriam-Webster.
  2. ^ Sukalyan Dash, Sabita Patel & Bijay K. Mishra (2009). "Oxidation by permanganate: synthetic and mechanistic aspects". Tetrahedron. 65 (4): 707–739. doi:10.1016/j.tet.2008.10.038.
  3. ^ "Geo-Cleanse International, INC. | Permanganate".