(NH4)2Cr2O7 💧⚡→ 2HNO2 + 2Cr + 3H2O
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- Electrolysis of aqueous ammonium dichromate without water as reactant
Electrolysis of aqueous ammonium dichromate yields nitrous acid, , 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
- 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 | 1 | Self redox agent | Very soluble in water |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HNO2 | Nitrous acid | 2 | Oxidized | – |
| 2 | Reduced | – | ||
| H2O | Water | 3 | – | – |
Thermodynamic changes
Changes in standard condition
- Electrolysis of aqueous ammonium dichromate without water as reactant◆
ΔrG 646.9 kJ/mol K 0.47 × 10−113 pK 113.33 - (NH4)2Cr2O7Ionized aqueous solution2HNO2Un-ionized aqueous solution + 2Crystalline solid + 3H2OLiquid💧⚡⟶
| 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 | 659.3 | 646.9 | 39.8 | – |
per 1 mol of | 659.3 | 646.9 | 39.8 | – |
per 1 mol of | 329.6 | 323.4 | 19.9 | – |
| 329.6 | 323.4 | 19.9 | – | |
per 1 mol of | 219.8 | 215.6 | 13.3 | – |
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 |
|---|---|---|---|---|
| HNO2 (g) cis | -77.99[1] | -42.94[1] | 248.76[1] | 44.77[1] |
| HNO2 (g) trans | -80.12[1] | -45.24[1] | 249.22[1] | 46.07[1] |
| HNO2 (g) | -79.5[1] | -46.0[1] | 254.1[1] | 45.6[1] |
| HNO2 (ao) | -119.2[1] | -50.6[1] | 135.6[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] |
* (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°, -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°, -77.99 kJ · mol−1
- ^ ΔfG°, -42.94 kJ · mol−1
- ^ S°, 248.76 J · K−1 · mol−1
- ^ Cp°, 44.77 J · K−1 · mol−1
- ^ ΔfH°, -80.12 kJ · mol−1
- ^ ΔfG°, -45.24 kJ · mol−1
- ^ S°, 249.22 J · K−1 · mol−1
- ^ Cp°, 46.07 J · K−1 · mol−1
- ^ ΔfH°, -79.5 kJ · mol−1
- ^ ΔfG°, -46.0 kJ · mol−1
- ^ S°, 254.1 J · K−1 · mol−1
- ^ Cp°, 45.6 J · K−1 · mol−1
- ^ ΔfH°, -119.2 kJ · mol−1
- ^ ΔfG°, -50.6 kJ · mol−1
- ^ S°, 135.6 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