14(NH4)2SO3 🔥→ 2N2O4 + 7(NH4)2S2O3 + 13H2O + 10NH3↑
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- Decomposition of ammonium sulfite
Decomposition of ammonium sulfite yields dinitrogen tetraoxide, ammonium thiosulfate, water, and ammonia (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 ammonium 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 ammonium sulfite
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)2SO3 | Ammonium sulfite | 14 | Reducing | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| N2O4 | Dinitrogen tetraoxide | 2 | Oxidized | – |
| (NH4)2S2O3 | Ammonium thiosulfate | 7 | Redoxed product | – |
| H2O | Water | 13 | – | – |
| NH3 | Ammonia | 10 | – | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Decomposition of ammonium sulfite
- 14(NH4)2SO3Ionized aqueous solution2N2O4Liquid + 7(NH4)2S2O3Aqueous solution + 13H2OLiquid + 10NH3↑Gas🔥⟶
| 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 | 1970.0 | – | – | – |
per 1 mol of | 140.71 | – | – | – |
per 1 mol of | 985.00 | – | – | – |
per 1 mol of | 281.43 | – | – | – |
per 1 mol of | 151.54 | – | – | – |
per 1 mol of | 197.00 | – | – | – |
Changes in aqueous solution (2)
- Decomposition of ammonium sulfite
- 14(NH4)2SO3Ionized aqueous solution2N2O4Liquid + 7(NH4)2S2O3Aqueous solution + 13H2OLiquid + 10NH3↑Un-ionized aqueous solution🔥⟶
| 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 | 1628.2 | – | – | – |
per 1 mol of | 116.30 | – | – | – |
per 1 mol of | 814.10 | – | – | – |
per 1 mol of | 232.60 | – | – | – |
per 1 mol of | 125.25 | – | – | – |
per 1 mol of | 162.82 | – | – | – |
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 |
|---|---|---|---|---|
| (NH4)2SO3 (cr) | -885.3[1] | – | – | – |
| (NH4)2SO3 (ai) | -900.4[1] | -645.0[1] | 197.5[1] | – |
| (NH4)2SO3 (cr) 1 hydrate | -1187.4[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 |
|---|---|---|---|---|
| N2O4 (l) | -19.50[1] | 97.54[1] | 209.2[1] | 142.7[1] |
| N2O4 (g) | 9.16[1] | 97.89[1] | 304.29[1] | 77.28[1] |
| (NH4)2S2O3 (aq) | -917.1[1] | – | – | – |
| H2O (cr) | – | – | – | – |
| H2O (l) | -285.830[1] | -237.129[1] | 69.91[1] | 75.291[1] |
| H2O (g) | -241.818[1] | -228.572[1] | 188.825[1] | 33.577[1] |
| NH3 (g) | -46.11[1] | -16.45[1] | 192.45[1] | 35.06[1] |
| NH3 (ao) | -80.29[1] | -26.50[1] | 111.3[1] | – |
* (l):Liquid, (g):Gas, (aq):Aqueous solution, (cr):Crystalline 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°, -885.3 kJ · mol−1
- ^ ΔfH°, -900.4 kJ · mol−1
- ^ ΔfG°, -645.0 kJ · mol−1
- ^ S°, 197.5 J · K−1 · mol−1
- ^ ΔfH°, -1187.4 kJ · mol−1
- ^ ΔfH°, -19.50 kJ · mol−1
- ^ ΔfG°, 97.54 kJ · mol−1
- ^ S°, 209.2 J · K−1 · mol−1
- ^ Cp°, 142.7 J · K−1 · mol−1
- ^ ΔfH°, 9.16 kJ · mol−1
- ^ ΔfG°, 97.89 kJ · mol−1
- ^ S°, 304.29 J · K−1 · mol−1
- ^ Cp°, 77.28 J · K−1 · mol−1
- ^ ΔfH°, -917.1 kJ · mol−1
- ^ ΔfH°, -285.830 kJ · mol−1
- ^ ΔfG°, -237.129 kJ · mol−1
- ^ S°, 69.91 J · K−1 · mol−1
- ^ Cp°, 75.291 J · K−1 · mol−1
- ^ ΔfH°, -241.818 kJ · mol−1
- ^ ΔfG°, -228.572 kJ · mol−1
- ^ S°, 188.825 J · K−1 · mol−1
- ^ Cp°, 33.577 J · K−1 · mol−1
- ^ ΔfH°, -46.11 kJ · mol−1
- ^ ΔfG°, -16.45 kJ · mol−1
- ^ S°, 192.45 J · K−1 · mol−1
- ^ Cp°, 35.06 J · K−1 · mol−1
- ^ ΔfH°, -80.29 kJ · mol−1
- ^ ΔfG°, -26.50 kJ · mol−1
- ^ S°, 111.3 J · K−1 · mol−1