(NH4)3AsO4 🔥→ NO↑ + As + 3H2O + 2NH3↑
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- Decomposition of ammonium arsenate
Decomposition of ammonium arsenate yields nitrogen monoxide, , 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 arsenate
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 arsenate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)3AsO4 | Ammonium arsenate | 1 | Self redox agent | Thermally decomposable Oxoacid salt |
Products
Thermodynamic changes
Changes in standard condition (1)
- Decomposition of ammonium arsenate
| 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 | 426.7 | – | – | – |
per 1 mol of | 426.7 | – | – | – |
per 1 mol of | 426.7 | – | – | – |
| 426.7 | – | – | – | |
per 1 mol of | 142.2 | – | – | – |
per 1 mol of | 213.3 | – | – | – |
Changes in standard condition (2)
- Decomposition of ammonium arsenate
| 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 | 441.3 | – | – | – |
per 1 mol of | 441.3 | – | – | – |
per 1 mol of | 441.3 | – | – | – |
| 441.3 | – | – | – | |
per 1 mol of | 147.1 | – | – | – |
per 1 mol of | 220.7 | – | – | – |
Changes in standard condition (3)
- Decomposition of ammonium arsenate
| 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 | 430.9 | – | – | – |
per 1 mol of | 430.9 | – | – | – |
per 1 mol of | 430.9 | – | – | – |
| 430.9 | – | – | – | |
per 1 mol of | 143.6 | – | – | – |
per 1 mol of | 215.4 | – | – | – |
Changes in aqueous solution (1)
- Decomposition of ammonium arsenate◆
ΔrG 228.58 kJ/mol K 0.90 × 10−40 pK 40.05 - (NH4)3AsO4Ionized aqueous solutionNO↑Gas + Crystalline solidα, gray, metallic + 3H2OLiquid + 2NH3↑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 | 426.20 | 228.58 | 663.1 | – |
per 1 mol of | 426.20 | 228.58 | 663.1 | – |
per 1 mol of | 426.20 | 228.58 | 663.1 | – |
| 426.20 | 228.58 | 663.1 | – | |
per 1 mol of | 142.07 | 76.193 | 221.0 | – |
per 1 mol of | 213.10 | 114.29 | 331.6 | – |
Changes in aqueous solution (2)
- Decomposition of ammonium arsenate◆
ΔrG 208.48 kJ/mol K 0.30 × 10−36 pK 36.52 - (NH4)3AsO4Ionized aqueous solutionNO↑Gas + Crystalline solidα, gray, metallic + 3H2OLiquid + 2NH3↑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 | 357.84 | 208.48 | 500.8 | – |
per 1 mol of | 357.84 | 208.48 | 500.8 | – |
per 1 mol of | 357.84 | 208.48 | 500.8 | – |
| 357.84 | 208.48 | 500.8 | – | |
per 1 mol of | 119.28 | 69.493 | 166.9 | – |
per 1 mol of | 178.92 | 104.24 | 250.4 | – |
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)3AsO4 (cr) | -1286.2[1] | – | – | – |
| (NH4)3AsO4 (ai) | -1285.66[1] | -886.32[1] | 177.4[1] | – |
| (NH4)3AsO4 (cr) 3 hydrate | -2166.9[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 |
|---|---|---|---|---|
| NO (g) | 90.25[1] | 86.55[1] | 210.761[1] | 29.844[1] |
| (cr) α, gray, metallic | 0[1] | 0[1] | 35.1[1] | 24.64[1] |
| (cr) γ, yellow, cubic | 14.6[1] | – | – | – |
| (am) β | 4.2[1] | – | – | – |
| (g) | 302.5[1] | 261.0[1] | 174.21[1] | 20.786[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] | – |
* (g):Gas, (cr):Crystalline solid, (am):Amorphous solid, (l):Liquid, (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°, -1286.2 kJ · mol−1
- ^ ΔfH°, -1285.66 kJ · mol−1
- ^ ΔfG°, -886.32 kJ · mol−1
- ^ S°, 177.4 J · K−1 · mol−1
- ^ ΔfH°, -2166.9 kJ · mol−1
- ^ ΔfH°, 90.25 kJ · mol−1
- ^ ΔfG°, 86.55 kJ · mol−1
- ^ S°, 210.761 J · K−1 · mol−1
- ^ Cp°, 29.844 J · K−1 · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 35.1 J · K−1 · mol−1
- ^ Cp°, 24.64 J · K−1 · mol−1
- ^ ΔfH°, 14.6 kJ · mol−1
- ^ ΔfH°, 4.2 kJ · mol−1
- ^ ΔfH°, 302.5 kJ · mol−1
- ^ ΔfG°, 261.0 kJ · mol−1
- ^ S°, 174.21 J · K−1 · mol−1
- ^ Cp°, 20.786 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
- ^ 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