2(NH4)2CO3 🔥→ 2NH4CN + O2↑ + 4H2O
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- Decomposition of ammonium carbonate
Decomposition of ammonium carbonate yields ammonium cyanide, , and water (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 carbonate
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 carbonate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)2CO3 | Ammonium carbonate | 2 | Self redox agent | Thermally decomposable Oxoacid salt |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NH4CN | Ammonium cyanide | 2 | Reduced | – |
| 1 | Oxidized | – | ||
| H2O | Water | 4 | – | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Decomposition of ammonium carbonate◆
ΔrG 610.3 kJ/mol K 0.12 × 10−106 pK 106.92
| 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 | 777.0 | 610.3 | 560.0 | – |
per 1 mol of | 388.5 | 305.1 | 280.0 | – |
per 1 mol of | 388.5 | 305.1 | 280.0 | – |
| 777.0 | 610.3 | 560.0 | – | |
per 1 mol of | 194.3 | 152.6 | 140.0 | – |
Changes in aqueous solution (2)
- Decomposition of ammonium carbonate◆
ΔrG 626.7 kJ/mol K 0.16 × 10−109 pK 109.79
| 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 | 765.3 | 626.7 | 465.7 | – |
per 1 mol of | 382.6 | 313.4 | 232.8 | – |
per 1 mol of | 382.6 | 313.4 | 232.8 | – |
| 765.3 | 626.7 | 465.7 | – | |
per 1 mol of | 191.3 | 156.7 | 116.4 | – |
Changes in aqueous solution (3)
- Decomposition of ammonium carbonate
| 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 | 805.4 | – | – | – |
per 1 mol of | 402.7 | – | – | – |
per 1 mol of | 402.7 | – | – | – |
| 805.4 | – | – | – | |
per 1 mol of | 201.3 | – | – | – |
Changes in aqueous solution (4)
- Decomposition of ammonium carbonate
| 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 | 793.7 | – | – | – |
per 1 mol of | 396.9 | – | – | – |
per 1 mol of | 396.9 | – | – | – |
| 793.7 | – | – | – | |
per 1 mol of | 198.4 | – | – | – |
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)2CO3 (ai) | -942.15[1] | -686.42[1] | 169.9[1] | – |
* (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 |
|---|---|---|---|---|
| NH4CN (cr) | 0.42[1] | – | – | 134[1] |
| NH4CN (ai) | 18.0[1] | 93.0[1] | 207.5[1] | – |
| NH4CN (aq) | 32.2[1] | – | – | – |
| (g) | 0[1] | 0[1] | 205.138[1] | 29.355[1] |
| (ao) | -11.7[1] | 16.4[1] | 110.9[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] |
* (cr):Crystalline solid, (ai):Ionized aqueous solution, (aq):Aqueous solution, (g):Gas, (ao):Un-ionized aqueous solution, (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)
- ^ ΔfH°, -942.15 kJ · mol−1
- ^ ΔfG°, -686.42 kJ · mol−1
- ^ S°, 169.9 J · K−1 · mol−1
- ^ ΔfH°, 0.42 kJ · mol−1
- ^ Cp°, 134. J · K−1 · mol−1
- ^ ΔfH°, 18.0 kJ · mol−1
- ^ ΔfG°, 93.0 kJ · mol−1
- ^ S°, 207.5 J · K−1 · mol−1
- ^ ΔfH°, 32.2 kJ · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 205.138 J · K−1 · mol−1
- ^ Cp°, 29.355 J · K−1 · mol−1
- ^ ΔfH°, -11.7 kJ · mol−1
- ^ ΔfG°, 16.4 kJ · mol−1
- ^ S°, 110.9 J · K−1 · 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