3H2 + (NH4)2Cr2O7 → Cr2O3 + 2NH3 + 4H2O
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- Reaction of and ammonium dichromate
The reaction of and ammonium dichromate yields chromium(III) oxide, ammonia, 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
- Reaction of and ammonium dichromate
General equation
- Reaction of reducing species and oxidizing species
- Reducing speciesReducing agent + Oxidizing speciesOxidizing agent ⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Reaction of and ammonium dichromate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| 3 | Reducing | Reducing | ||
| (NH4)2Cr2O7 | Ammonium dichromate | 1 | Oxidizing | Oxidizing |
Products
Thermodynamic changes
Changes in standard condition
- Reaction of and ammonium dichromate
| 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 | −568.5 | – | – | – |
| −189.5 | – | – | – | |
per 1 mol of | −568.5 | – | – | – |
per 1 mol of | −568.5 | – | – | – |
per 1 mol of | −284.3 | – | – | – |
per 1 mol of | −142.1 | – | – | – |
Changes in aqueous solution (1)
- Reaction of and ammonium dichromate◆
ΔrG −632.8 kJ/mol K 7.27 × 10110 pK −110.86 - 3Un-ionized aqueous solution + (NH4)2Cr2O7Ionized aqueous solutionCr2O3Crystalline solid + 2NH3Gas + 4H2OLiquid⟶
| 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 | −607.4 | −632.8 | −1474 | – |
| −202.5 | −210.9 | −491.3 | – | |
per 1 mol of | −607.4 | −632.8 | −1474 | – |
per 1 mol of | −607.4 | −632.8 | −1474 | – |
per 1 mol of | −303.7 | −316.4 | −737.0 | – |
per 1 mol of | −151.8 | −158.2 | −368.5 | – |
Changes in aqueous solution (2)
- Reaction of and ammonium dichromate◆
ΔrG −652.9 kJ/mol K 2.42 × 10114 pK −114.38 - 3Un-ionized aqueous solution + (NH4)2Cr2O7Ionized aqueous solutionCr2O3Crystalline solid + 2NH3Un-ionized aqueous solution + 4H2OLiquid⟶
| 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 | −675.8 | −652.9 | −1636 | – |
| −225.3 | −217.6 | −545.3 | – | |
per 1 mol of | −675.8 | −652.9 | −1636 | – |
per 1 mol of | −675.8 | −652.9 | −1636 | – |
per 1 mol of | −337.9 | −326.4 | −818.0 | – |
per 1 mol of | −168.9 | −163.2 | −409.0 | – |
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 |
|---|---|---|---|---|
| (g) | 0[1] | 0[1] | 130.684[1] | 28.824[1] |
| (ao) | -4.2[1] | 17.6[1] | 577[1] | – |
| (NH4)2Cr2O7 (cr) | -1806.7[1] | – | – | – |
| (NH4)2Cr2O7 (ai) | -1755.2[1] | -1459.5[1] | 488.7[1] | – |
* (g):Gas, (ao):Un-ionized aqueous solution, (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 |
|---|---|---|---|---|
| Cr2O3 (cr) | -1139.7[1] | -1058.1[1] | 81.2[1] | 118.74[1] |
| Cr2O3 (cr) 1 hydrate | -1506[1] | – | – | – |
| Cr2O3 (cr) 2 hydrate | -1845[1] | – | – | – |
| Cr2O3 (cr) 3 hydrate | -2171[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] | – |
| 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, (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°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 130.684 J · K−1 · mol−1
- ^ Cp°, 28.824 J · K−1 · mol−1
- ^ ΔfH°, -4.2 kJ · mol−1
- ^ ΔfG°, 17.6 kJ · mol−1
- ^ S°, 577 J · K−1 · mol−1
- ^ ΔfH°, -1806.7 kJ · mol−1
- ^ ΔfH°, -1755.2 kJ · mol−1
- ^ ΔfG°, -1459.5 kJ · mol−1
- ^ S°, 488.7 J · K−1 · mol−1
- ^ ΔfH°, -1139.7 kJ · mol−1
- ^ ΔfG°, -1058.1 kJ · mol−1
- ^ S°, 81.2 J · K−1 · mol−1
- ^ Cp°, 118.74 J · K−1 · mol−1
- ^ ΔfH°, -1506. kJ · mol−1
- ^ ΔfH°, -1845. kJ · mol−1
- ^ ΔfH°, -2171. kJ · 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°, -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