4(NH4)2CrO4 + 6e− → 8NH3↑ + Cr + 4H2O + 3CrO42−
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- Reduction of ammonium chromate
Reduction of ammonium chromate yields ammonia, , water, and chromate ion (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Reduction of ammonium chromate
General equation
- Reduction of reducible species
- ReactantOxidizing agent + e− ⟶ ProductReduction product
Oxidation state of each atom
- Reduction of ammonium chromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)2CrO4 | Ammonium chromate | 4 | Oxidizing | – |
| e− | Electron | 6 | – | Electron |
Products
Thermodynamic changes
Changes in standard condition (1)
- Reduction of ammonium chromate◆
ΔrG 282.07 kJ/mol K 0.38 × 10−49 pK 49.42 - 4(NH4)2CrO4Ionized aqueous solution + 6e−8NH3↑Gas + Crystalline solid + 4H2OLiquid + 3CrO42−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 | 428.99 | 282.07 | 885.6 | – |
per 1 mol of | 107.25 | 70.517 | 221.4 | – |
per 1 mol of Electron | 71.498 | 47.012 | 147.6 | – |
per 1 mol of | 53.624 | 35.259 | 110.7 | – |
| 428.99 | 282.07 | 885.6 | – | |
per 1 mol of | 107.25 | 70.517 | 221.4 | – |
per 1 mol of Chromate ion | 143.00 | 94.023 | 295.2 | – |
Changes in standard condition (2)
- Reduction of ammonium chromate◆
ΔrG 201.67 kJ/mol K 0.47 × 10−35 pK 35.33 - 4(NH4)2CrO4Ionized aqueous solution + 6e−8NH3↑Un-ionized aqueous solution + Crystalline solid + 4H2OLiquid + 3CrO42−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 | 155.55 | 201.67 | 236.4 | – |
per 1 mol of | 38.888 | 50.417 | 59.10 | – |
per 1 mol of Electron | 25.925 | 33.612 | 39.40 | – |
per 1 mol of | 19.444 | 25.209 | 29.55 | – |
| 155.55 | 201.67 | 236.4 | – | |
per 1 mol of | 38.888 | 50.417 | 59.10 | – |
per 1 mol of Chromate ion | 51.850 | 67.223 | 78.80 | – |
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)2CrO4 (cr) | -1167.3[1] | – | – | – |
| (NH4)2CrO4 (ai) | -1146.16[1] | -886.36[1] | 277.0[1] | – |
| e− | – | – | – | – |
* (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 |
|---|---|---|---|---|
| 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] | – |
| (cr) | 0[1] | 0[1] | 23.77[1] | 23.35[1] |
| (g) | 396.6[1] | 351.8[1] | 174.50[1] | 20.79[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] |
| CrO42− (ao) | -881.15[1] | -727.75[1] | 50.21[1] | – |
* (g):Gas, (ao):Un-ionized aqueous solution, (cr):Crystalline solid, (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°, -1167.3 kJ · mol−1
- ^ ΔfH°, -1146.16 kJ · mol−1
- ^ ΔfG°, -886.36 kJ · mol−1
- ^ S°, 277.0 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
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 23.77 J · K−1 · mol−1
- ^ Cp°, 23.35 J · K−1 · mol−1
- ^ ΔfH°, 396.6 kJ · mol−1
- ^ ΔfG°, 351.8 kJ · mol−1
- ^ S°, 174.50 J · K−1 · mol−1
- ^ Cp°, 20.79 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°, -881.15 kJ · mol−1
- ^ ΔfG°, -727.75 kJ · mol−1
- ^ S°, 50.21 J · K−1 · mol−1