Na2SiO3 🔥→ Na2O + SiO2
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- Decomposition of sodium metasilicate
Decomposition of sodium metasilicate yields sodium oxide and silicon dioxide (Other reactions are here). This reaction is an acid-base reaction and is classified as follows:
- Thermal decomposition without redox
- Thermal decomposition of oxoacid salt without redox
- Thermal decomposition of salt of oxoacid and hydroxide base
Table of contents
Reaction data
Chemical equation
- Decomposition of sodium metasilicate
General equation
- Thermal decomposition without redox
- Thermally decomposable substanceLewis conjugate🔥⟶ ProductLewis acid + ProductLewis base
- Thermal decomposition of oxoacid salt without redox
- Oxoacid saltLewis conjugate🔥⟶ Basic oxideLewis base + Acidic oxideLewis acid + (H2O)
- Thermal decomposition of salt of oxoacid and hydroxide base
- Salt of oxoacid and hydroxide baseLewis conjugate🔥⟶ Basic oxideLewis base + Acidic oxideLewis acid
Oxidation state of each atom
- Decomposition of sodium metasilicate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2SiO3 | Sodium metasilicate | 1 | Lewis conjugate | Thermally decomposable Oxoacid salt Salt of oxoacid and hydroxide base |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Na2O | Sodium oxide | 1 | Lewis acid Lewis base | – Basic oxide |
| SiO2 | Silicon dioxide | 1 | Lewis acid | – Acidic oxide |
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of sodium metasilicate◆
ΔrG 230.70 kJ/mol K 0.38 × 10−40 pK 40.42
| 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 | 229.74 | 230.70 | 3.05 | – |
per 1 mol of | 229.74 | 230.70 | 3.05 | – |
per 1 mol of | 229.74 | 230.70 | 3.05 | – |
per 1 mol of | 229.74 | 230.70 | 3.05 | – |
Changes in standard condition (2)
- Decomposition of sodium metasilicate◆
ΔrG 231.91 kJ/mol K 0.24 × 10−40 pK 40.63
| 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 | 231.20 | 231.91 | 3.89 | – |
per 1 mol of | 231.20 | 231.91 | 3.89 | – |
per 1 mol of | 231.20 | 231.91 | 3.89 | – |
per 1 mol of | 231.20 | 231.91 | 3.89 | – |
Changes in standard condition (3)
- Decomposition of sodium metasilicate◆
ΔrG 232.08 kJ/mol K 0.22 × 10−40 pK 40.66
| 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 | 231.62 | 232.08 | 4.7 | – |
per 1 mol of | 231.62 | 232.08 | 4.7 | – |
per 1 mol of | 231.62 | 232.08 | 4.7 | – |
per 1 mol of | 231.62 | 232.08 | 4.7 | – |
Changes in standard condition (4)
- Decomposition of sodium metasilicate◆
ΔrG 236.64 kJ/mol K 0.35 × 10−41 pK 41.46
| 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 | 237.19 | 236.64 | 8.1 | – |
per 1 mol of | 237.19 | 236.64 | 8.1 | – |
per 1 mol of | 237.19 | 236.64 | 8.1 | – |
per 1 mol of | 237.19 | 236.64 | 8.1 | – |
Changes in aqueous solution
- 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 | 275.0 | – | – | – |
per 1 mol of | 275.0 | – | – | – |
per 1 mol of | 275.0 | – | – | – |
per 1 mol of | 275.0 | – | – | – |
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] |
| SiO2 (cr) α-quartz | -910.94[1] | -856.64[1] | 41.84[1] | 44.43[1] |
| SiO2 (cr) α-cristobalite | -909.48[1] | -855.43[1] | 42.68[1] | 44.18[1] |
| SiO2 (cr) α-tridymite | -909.06[1] | -855.26[1] | 43.5[1] | 44.60[1] |
| SiO2 (am) | -903.49[1] | -850.70[1] | 46.9[1] | 44.4[1] |
| SiO2 (g) | -322[1] | – | – | – |
| SiO2 (ao) | -897.0[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°, -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°, -910.94 kJ · mol−1
- ^ ΔfG°, -856.64 kJ · mol−1
- ^ S°, 41.84 J · K−1 · mol−1
- ^ Cp°, 44.43 J · K−1 · mol−1
- ^ ΔfH°, -909.48 kJ · mol−1
- ^ ΔfG°, -855.43 kJ · mol−1
- ^ S°, 42.68 J · K−1 · mol−1
- ^ Cp°, 44.18 J · K−1 · mol−1
- ^ ΔfH°, -909.06 kJ · mol−1
- ^ ΔfG°, -855.26 kJ · mol−1
- ^ S°, 43.5 J · K−1 · mol−1
- ^ Cp°, 44.60 J · K−1 · mol−1
- ^ ΔfH°, -903.49 kJ · mol−1
- ^ ΔfG°, -850.70 kJ · mol−1
- ^ S°, 46.9 J · K−1 · mol−1
- ^ Cp°, 44.4 J · K−1 · mol−1
- ^ ΔfH°, -322. kJ · mol−1
- ^ ΔfH°, -897.0 kJ · mol−1