3(NH4)2Cr2O7 💧⚡→ 3NH4NO2 + 4Cr(OH)3 + Cr2O3
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- Electrolysis of aqueous ammonium dichromate without water as reactant
Electrolysis of aqueous ammonium dichromate yields ammonium nitrite, chromium(III) hydroxide, and chromium(III) oxide (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
- Electrolysis of aqueous ammonium dichromate without water as reactant
General equation
- Electrolysis of aqueous solution without water as reactant
- Miscible with water/Very soluble in water/Soluble in waterSelf redox agent💧⚡⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Electrolysis of aqueous ammonium dichromate without water as reactant
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| (NH4)2Cr2O7 | Ammonium dichromate | 3 | Self redox agent | Very soluble in water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| NH4NO2 | Ammonium nitrite | 3 | Oxidized | – |
| Cr(OH)3 | Chromium(III) hydroxide | 4 | Reduced | – |
| Cr2O3 | Chromium(III) oxide | 1 | Reduced | – |
Thermodynamic changes
Changes in standard condition
- Electrolysis of aqueous ammonium dichromate without water as reactant
- 3(NH4)2Cr2O7Crystalline solid3NH4NO2Crystalline solid + 4Cr(OH)3Crystalline solidprecipitated + Cr2O3Crystalline solid💧⚡⟶
| 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 | −745.1 | – | – | – |
per 1 mol of | −248.4 | – | – | – |
per 1 mol of | −248.4 | – | – | – |
per 1 mol of | −186.3 | – | – | – |
per 1 mol of | −745.1 | – | – | – |
Changes in aqueous solution
- Electrolysis of aqueous ammonium dichromate without water as reactant
- 3(NH4)2Cr2O7Ionized aqueous solution3NH4NO2Ionized aqueous solution + 4Cr(OH)3Crystalline solidprecipitated + Cr2O3Crystalline solid💧⚡⟶
| 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 | −841.7 | – | – | – |
per 1 mol of | −280.6 | – | – | – |
per 1 mol of | −280.6 | – | – | – |
per 1 mol of | −210.4 | – | – | – |
per 1 mol of | −841.7 | – | – | – |
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)2Cr2O7 (cr) | -1806.7[1] | – | – | – |
| (NH4)2Cr2O7 (ai) | -1755.2[1] | -1459.5[1] | 488.7[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 |
|---|---|---|---|---|
| NH4NO2 (cr) | -256.5[1] | – | – | – |
| NH4NO2 (ai) | -237.2[1] | -111.6[1] | 236.4[1] | -17.6[1] |
| Cr(OH)3 (cr) precipitated | -1064.0[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] | – | – | – |
* (cr):Crystalline solid, (ai):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°, -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°, -256.5 kJ · mol−1
- ^ ΔfH°, -237.2 kJ · mol−1
- ^ ΔfG°, -111.6 kJ · mol−1
- ^ S°, 236.4 J · K−1 · mol−1
- ^ Cp°, -17.6 J · K−1 · mol−1
- ^ ΔfH°, -1064.0 kJ · 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