4KMnO4 + 3e− → 2K2O + MnO2 + 3MnO4−
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- Reduction of potassium permanganate
- 4KMnO4Potassium permanganate + 3e−Electron2K2OPotassium oxide + MnO2Manganese(IV) oxide + 3MnO4−Permanganate ion⟶
Reduction of potassium permanganate yields potassium oxide, manganese(IV) oxide, and permanganate ion (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reduction of potassium permanganate
- 4KMnO4Potassium permanganate + 3e−Electron2K2OPotassium oxide + MnO2Manganese(IV) oxide + 3MnO4−Permanganate ion⟶
General equation
- Reduction of reducible species
- ReactantOxidizing agent + e− ⟶ ProductReduction product
Oxidation state of each atom
- Reduction of potassium permanganate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| KMnO4 | Potassium permanganate | 4 | Oxidizing | – |
| e− | Electron | 3 | – | Electron |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2O | Potassium oxide | 2 | – | – |
| MnO2 | Manganese(IV) oxide | 1 | Reduced | – |
| MnO4− | Permanganate ion | 3 | – | – |
Thermodynamic changes
Changes in standard condition
- Reduction of potassium permanganate◆
ΔrG 471.1 kJ/mol K 0.29 × 10−82 pK 82.53
| Standard enthalpy of reaction ΔrH° kJ · mol−1 | Standard Gibbs energy of reaction ΔrG° kJ · mol−1 | Standard entropy of reaction ΔrS° J · K−1 · mol−1 | Standard heat capacity of reaction at constant pressure ΔrCp° J · K−1 · mol−1 | |
|---|---|---|---|---|
per 1 mol of Equation | 308.0 | 471.1 | −360.0 | 216.3 |
per 1 mol of | 77.00 | 117.8 | −90.00 | 54.08 |
per 1 mol of Electron | 102.7 | 157.0 | −120.0 | 72.10 |
per 1 mol of | 154.0 | 235.6 | −180.0 | 108.2 |
per 1 mol of | 308.0 | 471.1 | −360.0 | 216.3 |
per 1 mol of Permanganate ion | 102.7 | 157.0 | −120.0 | 72.10 |
Thermodynamic data of reactants
| Chemical formula | Standard enthalpy of formation ΔfH° kJ · mol−1 | Standard Gibbs energy of formation ΔfG° kJ · mol−1 | Standard molar entropy S° J · K−1 · mol−1 | Standard molar heat capacity at constant pressure Cp° J · K−1 · mol−1 |
|---|---|---|---|---|
| KMnO4 (cr) | -837.2[1] | -737.6[1] | 171.71[1] | 117.57[1] |
| KMnO4 (ai) | -793.8[1] | -730.5[1] | 293.7[1] | -60.2[1] |
| e− | – | – | – | – |
* (cr):Crystalline solid, (ai):Ionized aqueous solution
Thermodynamic data of products
| Chemical formula | Standard enthalpy of formation ΔfH° kJ · mol−1 | Standard Gibbs energy of formation ΔfG° kJ · mol−1 | Standard molar entropy S° J · K−1 · mol−1 | Standard molar heat capacity at constant pressure Cp° J · K−1 · mol−1 |
|---|---|---|---|---|
| K2O (cr) | -361.5[1] | -322.1[2] | 94.1[2] | 83.7[2] |
| K2O (g) | -63[1] | – | – | – |
| MnO2 (cr) | -520.03[1] | -465.14[1] | 53.05[1] | 54.14[1] |
| MnO2 (am) precipitated | -502.5[1] | – | – | – |
| MnO4− (ao) | -541.4[1] | -447.2[1] | 191.2[1] | -82.0[1] |
* (cr):Crystalline solid, (g):Gas, (am):Amorphous solid, (ao):Un-ionized aqueous solution
References
List of references
- 1Janiel J. Reed (1989)The NBS Tables of Chemical Thermodynamic Properties: Selected Values for Inorganic and C1 and C2 Organic Substances in SI UnitsNational Institute of Standards and Technology (NIST)
- ^ ΔfH°, -837.2 kJ · mol−1
- ^ ΔfG°, -737.6 kJ · mol−1
- ^ S°, 171.71 J · K−1 · mol−1
- ^ Cp°, 117.57 J · K−1 · mol−1
- ^ ΔfH°, -793.8 kJ · mol−1
- ^ ΔfG°, -730.5 kJ · mol−1
- ^ S°, 293.7 J · K−1 · mol−1
- ^ Cp°, -60.2 J · K−1 · mol−1
- ^ ΔfH°, -361.5 kJ · mol−1
- ^ ΔfH°, -63. kJ · mol−1
- ^ ΔfH°, -520.03 kJ · mol−1
- ^ ΔfG°, -465.14 kJ · mol−1
- ^ S°, 53.05 J · K−1 · mol−1
- ^ Cp°, 54.14 J · K−1 · mol−1
- ^ ΔfH°, -502.5 kJ · mol−1
- ^ ΔfH°, -541.4 kJ · mol−1
- ^ ΔfG°, -447.2 kJ · mol−1
- ^ S°, 191.2 J · K−1 · mol−1
- ^ Cp°, -82.0 J · K−1 · mol−1
- 2James G. Speight (2017)Lange's Handbook of Chemistry, 17th editionMcGraw Hill Education
- ^ ΔfG°, -322.1 kJ · mol−1 - p.280
- ^ S°, 94.1 J · K−1 · mol−1 - p.280
- ^ Cp°, 83.7 J · K−1 · mol−1 - p.280