3Na2SiO3 🔥→ 3Na2O + 3Si + 2O3↑
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- Decomposition of sodium metasilicate
Decomposition of sodium metasilicate yields sodium 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 metasilicate
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 metasilicate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2SiO3 | Sodium metasilicate | 3 | Self redox agent | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2O | Sodium oxide | 3 | – | – |
| 3 | Reduced | – | ||
| 2 | Oxidized | – |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of sodium metasilicate◆
ΔrG 3588.4 kJ/mol K 0.22 × 10−628 pK 628.66
| 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 | 3707.4 | 3588.4 | 417.98 | – |
per 1 mol of | 1235.8 | 1196.1 | 139.33 | – |
per 1 mol of | 1235.8 | 1196.1 | 139.33 | – |
| 1235.8 | 1196.1 | 139.33 | – | |
| 1853.7 | 1794.2 | 208.99 | – |
Changes in standard condition (2)
- Decomposition of sodium metasilicate
| 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 | 3720.0 | – | – | – |
per 1 mol of | 1240.0 | – | – | – |
per 1 mol of | 1240.0 | – | – | – |
| 1240.0 | – | – | – | |
| 1860.0 | – | – | – |
Changes in aqueous solution (1)
- Decomposition of sodium metasilicate
| 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 | 3801.3 | – | – | – |
per 1 mol of | 1267.1 | – | – | – |
per 1 mol of | 1267.1 | – | – | – |
| 1267.1 | – | – | – | |
| 1900.7 | – | – | – |
Changes in aqueous solution (2)
- Decomposition of sodium metasilicate
| 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 | 3767.7 | – | – | – |
per 1 mol of | 1255.9 | – | – | – |
per 1 mol of | 1255.9 | – | – | – |
| 1255.9 | – | – | – | |
| 1883.8 | – | – | – |
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 |
|---|---|---|---|---|
| Na2SiO3 (cr) | -1554.90[1] | -1462.80[1] | 113.85[1] | – |
| Na2SiO3 (vit) | -1540.1[1] | – | – | – |
| Na2SiO3 (aq) | -1586.2[1] | – | – | – |
| Na2SiO3 (cr) 5 hydrate | -3048.5[1] | – | – | – |
| Na2SiO3 (cr) 9 hydrate | -4228.8[1] | – | – | – |
* (cr):Crystalline solid, (vit):Vitreous liquid, (aq):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] |
| (cr) | 0[1] | 0[1] | 18.83[1] | 20.00[1] |
| (am) | 4.2[1] | – | – | – |
| (g) | 455.6[1] | 411.3[1] | 167.97[1] | 22.251[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°, -1554.90 kJ · mol−1
- ^ ΔfG°, -1462.80 kJ · mol−1
- ^ S°, 113.85 J · K−1 · mol−1
- ^ ΔfH°, -1540.1 kJ · mol−1
- ^ ΔfH°, -1586.2 kJ · mol−1
- ^ ΔfH°, -3048.5 kJ · mol−1
- ^ ΔfH°, -4228.8 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°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 18.83 J · K−1 · mol−1
- ^ Cp°, 20.00 J · K−1 · mol−1
- ^ ΔfH°, 4.2 kJ · mol−1
- ^ ΔfH°, 455.6 kJ · mol−1
- ^ ΔfG°, 411.3 kJ · mol−1
- ^ S°, 167.97 J · K−1 · mol−1
- ^ Cp°, 22.251 J · K−1 · 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