3K2SeO3 🔥→ 2K2SeO4 + K2O + Se
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- Decomposition of potassium selenite
Decomposition of potassium selenite yields potassium selenate, potassium 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 potassium selenite
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 potassium selenite
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2SeO3 | Potassium selenite | 3 | – | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| K2SeO4 | Potassium selenate | 2 | Oxidized | – |
| K2O | Potassium oxide | 1 | – | – |
| 1 | Reduced | – |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of potassium selenite
| 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 | 364.5 | – | – | – |
per 1 mol of | 121.5 | – | – | – |
per 1 mol of | 182.3 | – | – | – |
per 1 mol of | 364.5 | – | – | – |
| 364.5 | – | – | – |
Changes in standard condition (2)
- Decomposition of potassium selenite
| 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 | 371.2 | – | – | – |
per 1 mol of | 123.7 | – | – | – |
per 1 mol of | 185.6 | – | – | – |
per 1 mol of | 371.2 | – | – | – |
| 371.2 | – | – | – |
Changes in aqueous solution
- Decomposition of potassium selenite◆
ΔrG 471.0 kJ/mol K 0.31 × 10−82 pK 82.52
| 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 | 472.5 | 471.0 | 0.5 | – |
per 1 mol of | 157.5 | 157.0 | 0.17 | – |
per 1 mol of | 236.3 | 235.5 | 0.25 | – |
per 1 mol of | 472.5 | 471.0 | 0.50 | – |
| 472.5 | 471.0 | 0.50 | – |
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 |
|---|---|---|---|---|
| K2SeO3 (cr) | -982.0[1] | – | – | – |
| K2SeO3 (ai) | -1013.8[1] | -936.3[1] | 218.0[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 |
|---|---|---|---|---|
| K2SeO4 (cr) | -1110.02[1] | -1002.8[1] | 222[1] | – |
| K2SeO4 (ai) | -1103.7[1] | -1007.9[1] | 259.0[1] | – |
| K2O (cr) | -361.5[1] | -322.1[2] | 94.1[2] | 83.7[2] |
| K2O (g) | -63[1] | – | – | – |
| (cr) hexagonal, gray | 0[1] | 0[1] | 42.442[1] | 25.363[1] |
| (cr) monoclinic, red | 6.7[1] | – | – | – |
| (vit) | 5.0[1] | – | – | – |
| (g) | 227.07[1] | 187.03[1] | 176.72[1] | 20.820[1] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (g):Gas, (vit):Vitreous liquid
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°, -982.0 kJ · mol−1
- ^ ΔfH°, -1013.8 kJ · mol−1
- ^ ΔfG°, -936.3 kJ · mol−1
- ^ S°, 218.0 J · K−1 · mol−1
- ^ ΔfH°, -1110.02 kJ · mol−1
- ^ ΔfG°, -1002.8 kJ · mol−1
- ^ S°, 222. J · K−1 · mol−1
- ^ ΔfH°, -1103.7 kJ · mol−1
- ^ ΔfG°, -1007.9 kJ · mol−1
- ^ S°, 259.0 J · K−1 · mol−1
- ^ ΔfH°, -361.5 kJ · mol−1
- ^ ΔfH°, -63. kJ · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 42.442 J · K−1 · mol−1
- ^ Cp°, 25.363 J · K−1 · mol−1
- ^ ΔfH°, 6.7 kJ · mol−1
- ^ ΔfH°, 5.0 kJ · mol−1
- ^ ΔfH°, 227.07 kJ · mol−1
- ^ ΔfG°, 187.03 kJ · mol−1
- ^ S°, 176.72 J · K−1 · mol−1
- ^ Cp°, 20.820 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