2HS− + 2e− → H2 + 2S2−
Last updated:
Reduction of hydrogensulfide ion yields and sulfide ion (Other reactions are here). This reaction is an oxidation-reduction reaction and is classified as follows:
Table of contents
Reaction data
Chemical equation
General equation
- Reduction of reducible species
- ReactantOxidizing agent + e− ⟶ ProductReduction product
Oxidation state of each atom
- Reduction of hydrogensulfide ion
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HS− | Hydrogensulfide ion | 2 | Oxidizing | – |
| e− | Electron | 2 | – | Electron |
Products
Thermodynamic changes
Changes in standard condition (1)
- Reduction of hydrogensulfide ion◆
ΔrG 147.4 kJ/mol K 0.15 × 10−25 pK 25.82 - 2HS−Un-ionized aqueous solution + 2e−Gas + 2S2−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 | 101.4 | 147.4 | −24.1 | – |
per 1 mol of Hydrogensulfide ion | 50.70 | 73.70 | −12.1 | – |
per 1 mol of Electron | 50.70 | 73.70 | −12.1 | – |
| 101.4 | 147.4 | −24.1 | – | |
per 1 mol of Sulfide ion | 50.70 | 73.70 | −12.1 | – |
Changes in standard condition (2)
- Reduction of hydrogensulfide ion◆
ΔrG 165.0 kJ/mol K 0.12 × 10−28 pK 28.91 - 2HS−Un-ionized aqueous solution + 2e−Un-ionized aqueous solution + 2S2−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 | 97.2 | 165.0 | 422 | – |
per 1 mol of Hydrogensulfide ion | 48.6 | 82.50 | 211 | – |
per 1 mol of Electron | 48.6 | 82.50 | 211 | – |
| 97.2 | 165.0 | 422 | – | |
per 1 mol of Sulfide ion | 48.6 | 82.50 | 211 | – |
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 |
|---|---|---|---|---|
| HS− (ao) | -17.6[1] | 12.08[1] | 62.8[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 |
|---|---|---|---|---|
| (g) | 0[1] | 0[1] | 130.684[1] | 28.824[1] |
| (ao) | -4.2[1] | 17.6[1] | 577[1] | – |
| S2− (ao) | 33.1[1] | 85.8[1] | -14.6[1] | – |
* (g):Gas, (ao):Un-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°, -17.6 kJ · mol−1
- ^ ΔfG°, 12.08 kJ · mol−1
- ^ S°, 62.8 J · K−1 · mol−1
- ^ 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°, 33.1 kJ · mol−1
- ^ ΔfG°, 85.8 kJ · mol−1
- ^ S°, -14.6 J · K−1 · mol−1