4CaSO3 🔥→ CaS + 3CaO + 3SO3
Last updated:
- Decomposition of calcium sulfite
Decomposition of calcium sulfite yields calcium sulfide, calcium oxide, and sulfur trioxide (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 calcium sulfite
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 calcium sulfite
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| CaSO3 | Calcium sulfite | 4 | – | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| CaS | Calcium sulfide | 1 | Reduced | – |
| CaO | Calcium oxide | 3 | – | – |
| SO3 | Sulfur trioxide | 3 | Oxidized | – |
Thermodynamic changes
Changes in standard condition
- Decomposition of calcium sulfite
| 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 | – | – | 111.6 | – |
per 1 mol of | – | – | 27.90 | – |
per 1 mol of | – | – | 111.6 | – |
per 1 mol of | – | – | 37.20 | – |
per 1 mol of | – | – | 37.20 | – |
Changes in aqueous solution
- Decomposition of calcium sulfite
| 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 | – | – | −17.7 | – |
per 1 mol of | – | – | −4.42 | – |
per 1 mol of | – | – | −17.7 | – |
per 1 mol of | – | – | −5.90 | – |
per 1 mol of | – | – | −5.90 | – |
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 |
|---|---|---|---|---|
| CaSO3 (cr) | – | – | 101.38[1] | 91.71[1] |
| CaSO3 (cr) 0.5 hydrate | -1311.7[1] | -1199.23[1] | 121.3[1] | – |
* (cr):Crystalline solid
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 |
|---|---|---|---|---|
| CaS (cr) | -482.4[1] | -477.4[1] | 56.5[1] | 47.40[1] |
| CaS (g) | – | – | – | – |
| CaO (cr) | -635.09[1] | -604.03[1] | 39.75[1] | 42.80[1] |
| CaO (g) | – | – | – | – |
| SO3 (cr) β | -454.51[1] | -374.21[1] | 70.7[1] | – |
| SO3 (l) | -441.04[1] | -373.75[1] | 113.8[1] | – |
| SO3 (g) | -395.72[1] | -371.06[1] | 256.76[1] | 50.67[1] |
* (cr):Crystalline solid, (g):Gas, (l):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)
- ^ S°, 101.38 J · K−1 · mol−1
- ^ Cp°, 91.71 J · K−1 · mol−1
- ^ ΔfH°, -1311.7 kJ · mol−1
- ^ ΔfG°, -1199.23 kJ · mol−1
- ^ S°, 121.3 J · K−1 · mol−1
- ^ ΔfH°, -482.4 kJ · mol−1
- ^ ΔfG°, -477.4 kJ · mol−1
- ^ S°, 56.5 J · K−1 · mol−1
- ^ Cp°, 47.40 J · K−1 · mol−1
- ^ ΔfH°, -635.09 kJ · mol−1
- ^ ΔfG°, -604.03 kJ · mol−1
- ^ S°, 39.75 J · K−1 · mol−1
- ^ Cp°, 42.80 J · K−1 · mol−1
- ^ ΔfH°, -454.51 kJ · mol−1
- ^ ΔfG°, -374.21 kJ · mol−1
- ^ S°, 70.7 J · K−1 · mol−1
- ^ ΔfH°, -441.04 kJ · mol−1
- ^ ΔfG°, -373.75 kJ · mol−1
- ^ S°, 113.8 J · K−1 · mol−1
- ^ ΔfH°, -395.72 kJ · mol−1
- ^ ΔfG°, -371.06 kJ · mol−1
- ^ S°, 256.76 J · K−1 · mol−1
- ^ Cp°, 50.67 J · K−1 · mol−1