3(NH4)2Cr2O7 💧⚡→ 3N2H4 + 4Cr(OH)3 + Cr2O3 + 2O3↑
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- Electrolysis of aqueous ammonium dichromate without water as reactant
Electrolysis of aqueous ammonium dichromate yields hydrazine, chromium(III) hydroxide, chromium(III) oxide, and (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 |
|---|---|---|---|---|
| N2H4 | Hydrazine | 3 | Oxidized | – |
| Cr(OH)3 | Chromium(III) hydroxide | 4 | Reduced | – |
| Cr2O3 | Chromium(III) oxide | 1 | Reduced | – |
| 2 | Oxidized | – |
Thermodynamic changes
Changes in standard condition
- Electrolysis of aqueous ammonium dichromate without water as reactant
- 3(NH4)2Cr2O7Crystalline solid3N2H4Liquid + 4Cr(OH)3Crystalline solidprecipitated + Cr2O3Crystalline solid + 2↑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 | 461.7 | – | – | – |
per 1 mol of | 153.9 | – | – | – |
per 1 mol of | 153.9 | – | – | – |
per 1 mol of | 115.4 | – | – | – |
per 1 mol of | 461.7 | – | – | – |
| 230.8 | – | – | – |
Changes in aqueous solution (1)
- Electrolysis of aqueous ammonium dichromate without water as reactant
- 3(NH4)2Cr2O7Ionized aqueous solution3N2H4Un-ionized aqueous solution + 4Cr(OH)3Crystalline solidprecipitated + Cr2O3Crystalline solid + 2↑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 | 258.2 | – | – | – |
per 1 mol of | 86.07 | – | – | – |
per 1 mol of | 86.07 | – | – | – |
per 1 mol of | 64.55 | – | – | – |
per 1 mol of | 258.2 | – | – | – |
| 129.1 | – | – | – |
Changes in aqueous solution (2)
- Electrolysis of aqueous ammonium dichromate without water as reactant
- 3(NH4)2Cr2O7Ionized aqueous solution3N2H4Un-ionized aqueous solution + 4Cr(OH)3Crystalline solidprecipitated + Cr2O3Crystalline solid + 2↑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 | 224.6 | – | – | – |
per 1 mol of | 74.87 | – | – | – |
per 1 mol of | 74.87 | – | – | – |
per 1 mol of | 56.15 | – | – | – |
per 1 mol of | 224.6 | – | – | – |
| 112.3 | – | – | – |
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 |
|---|---|---|---|---|
| N2H4 (l) | 50.63[1] | 149.34[1] | 121.21[1] | 98.87[1] |
| N2H4 (g) | 95.40[1] | 159.35[1] | 238.47[1] | 49.58[1] |
| N2H4 (ao) | 34.31[1] | 128.1[1] | 138[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] | – | – | – |
| (g) | 142.7[1] | 163.2[1] | 238.93[1] | 39.20[1] |
| (ao) | 125.9[1] | 174.1[1] | 146[1] | – |
* (l):Liquid, (g):Gas, (ao):Un-ionized aqueous solution, (cr):Crystalline solid
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°, 50.63 kJ · mol−1
- ^ ΔfG°, 149.34 kJ · mol−1
- ^ S°, 121.21 J · K−1 · mol−1
- ^ Cp°, 98.87 J · K−1 · mol−1
- ^ ΔfH°, 95.40 kJ · mol−1
- ^ ΔfG°, 159.35 kJ · mol−1
- ^ S°, 238.47 J · K−1 · mol−1
- ^ Cp°, 49.58 J · K−1 · mol−1
- ^ ΔfH°, 34.31 kJ · mol−1
- ^ ΔfG°, 128.1 kJ · mol−1
- ^ S°, 138. 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
- ^ ΔfH°, 142.7 kJ · mol−1
- ^ ΔfG°, 163.2 kJ · mol−1
- ^ S°, 238.93 J · K−1 · mol−1
- ^ Cp°, 39.20 J · K−1 · mol−1
- ^ ΔfH°, 125.9 kJ · mol−1
- ^ ΔfG°, 174.1 kJ · mol−1
- ^ S°, 146. J · K−1 · mol−1