4HSO4− + 2e− → H2SO3 + H2O + 3SO42−
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- Reduction of hydrogensulfate ion
Reduction of hydrogensulfate ion yields sulfurous acid, water, and sulfate 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 hydrogensulfate ion
General equation
- Reduction of reducible species
- ReactantOxidizing agent + e− ⟶ ProductReduction product
Oxidation state of each atom
- Reduction of hydrogensulfate ion
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HSO4− | Hydrogensulfate ion | 4 | Oxidizing | – |
| e− | Electron | 2 | – | Electron |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| H2SO3 | Sulfurous acid | 1 | Reduced | – |
| H2O | Water | 1 | – | – |
| SO42− | Sulfate ion | 3 | – | – |
Thermodynamic changes
Changes in standard condition
- Reduction of hydrogensulfate ion◆
ΔrG 15.11 kJ/mol K 0.23 × 10−2 pK 2.65
| 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 | −73.09 | 15.11 | −164.8 | – |
per 1 mol of Hydrogensulfate ion | −18.27 | 3.777 | −41.20 | – |
per 1 mol of Electron | −36.55 | 7.555 | −82.40 | – |
per 1 mol of | −73.09 | 15.11 | −164.8 | – |
per 1 mol of | −73.09 | 15.11 | −164.8 | – |
per 1 mol of Sulfate ion | −24.36 | 5.037 | −54.93 | – |
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 |
|---|---|---|---|---|
| HSO4− (ao) | -887.34[1] | -755.91[1] | 131.8[1] | -84[1] |
| e− | – | – | – | – |
* (ao):Un-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 |
|---|---|---|---|---|
| H2SO3 (ao) | -608.81[1] | -537.81[1] | 232.2[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] |
| SO42− (ao) | -909.27[1] | -744.53[1] | 20.1[1] | -293[1] |
* (ao):Un-ionized aqueous solution, (cr):Crystalline solid, (l):Liquid, (g):Gas
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°, -887.34 kJ · mol−1
- ^ ΔfG°, -755.91 kJ · mol−1
- ^ S°, 131.8 J · K−1 · mol−1
- ^ Cp°, -84. J · K−1 · mol−1
- ^ ΔfH°, -608.81 kJ · mol−1
- ^ ΔfG°, -537.81 kJ · mol−1
- ^ S°, 232.2 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°, -909.27 kJ · mol−1
- ^ ΔfG°, -744.53 kJ · mol−1
- ^ S°, 20.1 J · K−1 · mol−1
- ^ Cp°, -293. J · K−1 · mol−1