3Na2MnO4 🔥→ 3Na2O + 3MnO2 + O3↑
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- Decomposition of sodium manganate
Decomposition of sodium manganate yields sodium oxide, manganese(IV) oxide, and (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 | Self redox agent | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2O | Sodium oxide | 3 | – | – |
| MnO2 | Manganese(IV) oxide | 3 | Reduced | – |
| 1 | Oxidized | – |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of sodium manganate
| 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 | 808.0 | – | – | – |
per 1 mol of | 269.3 | – | – | – |
per 1 mol of | 269.3 | – | – | – |
per 1 mol of | 269.3 | – | – | – |
| 808.0 | – | – | – |
Changes in standard condition (2)
- Decomposition of sodium manganate
| 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 | 860.5 | – | – | – |
per 1 mol of | 286.8 | – | – | – |
per 1 mol of | 286.8 | – | – | – |
per 1 mol of | 286.8 | – | – | – |
| 860.5 | – | – | – |
Changes in aqueous solution (1)
- Decomposition of sodium manganate◆
ΔrG 715.2 kJ/mol K 0.50 × 10−125 pK 125.30
| 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 | 742 | 715.2 | 95 | – |
per 1 mol of | 247 | 238.4 | 32 | – |
per 1 mol of | 247 | 238.4 | 32 | – |
per 1 mol of | 247 | 238.4 | 32 | – |
| 742 | 715.2 | 95 | – |
Changes in aqueous solution (2)
- Decomposition of sodium manganate◆
ΔrG 726.1 kJ/mol K 0.62 × 10−127 pK 127.21
| 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 | 725 | 726.1 | 2 | – |
per 1 mol of | 242 | 242.0 | 0.7 | – |
per 1 mol of | 242 | 242.0 | 0.7 | – |
per 1 mol of | 242 | 242.0 | 0.7 | – |
| 725 | 726.1 | 2 | – |
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 |
|---|---|---|---|---|
| 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] | – | – | – |
| (g) | 142.7[1] | 163.2[1] | 238.93[1] | 39.20[1] |
| (ao) | 125.9[1] | 174.1[1] | 146[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°, -1156.0 kJ · mol−1
- ^ ΔfH°, -1134. kJ · mol−1
- ^ ΔfG°, -1024.6 kJ · mol−1
- ^ S°, 176. J · K−1 · 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
- ^ ΔfH°, 142.7 kJ · mol−1
- ^ ΔfG°, 163.2 kJ · mol−1
- ^ S°, 238.93 J · K−1 · mol−1
- ^ Cp°, 39.20 J · K−1 · mol−1
- ^ ΔfH°, 125.9 kJ · mol−1
- ^ ΔfG°, 174.1 kJ · mol−1
- ^ S°, 146. J · K−1 · mol−1