3Na2MnO4 🔥→ 2NaMnO4 + 2Na2O + MnO2
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- Decomposition of sodium manganate
Decomposition of sodium manganate yields sodium permanganate, sodium oxide, and manganese(IV) oxide (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Decomposition of sodium manganate
General equation
- Thermal decomposition with redox
- Thermally decomposable substanceSelf redox agent🔥⟶ ProductOxidation product + ProductReduction product
- Thermal decomposition of oxoacid salt with redox
- Oxoacid saltSelf redox agent🔥⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Decomposition of sodium manganate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2MnO4 | Sodium manganate | 3 | – | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NaMnO4 | Sodium permanganate | 2 | Oxidized | – |
| Na2O | Sodium oxide | 2 | – | – |
| MnO2 | Manganese(IV) oxide | 1 | Reduced | – |
Thermodynamic changes
Changes in aqueous solution
- Decomposition of sodium manganate◆
ΔrG 439.5 kJ/mol K 0.10 × 10−76 pK 77.00
| 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 | 490 | 439.5 | 176 | – |
per 1 mol of | 163 | 146.5 | 58.7 | – |
per 1 mol of | 245 | 219.8 | 88.0 | – |
per 1 mol of | 245 | 219.8 | 88.0 | – |
per 1 mol of | 490 | 439.5 | 176 | – |
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 |
|---|---|---|---|---|
| Na2MnO4 (cr) | -1156.0[1] | – | – | – |
| Na2MnO4 (ai) | -1134[1] | -1024.6[1] | 176[1] | – |
* (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 |
|---|---|---|---|---|
| NaMnO4 (ai) | -781.6[1] | -709.1[1] | 250.2[1] | – |
| NaMnO4 (cr) 1 hydrate | -1079.14[1] | – | – | – |
| NaMnO4 (cr) 3 hydrate | -1672.85[1] | – | – | – |
| Na2O (cr) | -414.22[1] | -375.46[1] | 75.06[1] | 69.12[1] |
| Na2O (g) | -35.6[1] | -52.3[1] | 261.2[1] | 55.2[1] |
| MnO2 (cr) | -520.03[1] | -465.14[1] | 53.05[1] | 54.14[1] |
| MnO2 (am) precipitated | -502.5[1] | – | – | – |
* (ai):Ionized aqueous solution, (cr):Crystalline solid, (g):Gas, (am):Amorphous solid
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°, -1156.0 kJ · mol−1
- ^ ΔfH°, -1134. kJ · mol−1
- ^ ΔfG°, -1024.6 kJ · mol−1
- ^ S°, 176. J · K−1 · mol−1
- ^ ΔfH°, -781.6 kJ · mol−1
- ^ ΔfG°, -709.1 kJ · mol−1
- ^ S°, 250.2 J · K−1 · mol−1
- ^ ΔfH°, -1079.14 kJ · mol−1
- ^ ΔfH°, -1672.85 kJ · mol−1
- ^ ΔfH°, -414.22 kJ · mol−1
- ^ ΔfG°, -375.46 kJ · mol−1
- ^ S°, 75.06 J · K−1 · mol−1
- ^ Cp°, 69.12 J · K−1 · mol−1
- ^ ΔfH°, -35.6 kJ · mol−1
- ^ ΔfG°, -52.3 kJ · mol−1
- ^ S°, 261.2 J · K−1 · mol−1
- ^ Cp°, 55.2 J · K−1 · 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