5H2S + 2K3AsO4 → 2S + 2H3AsO3 + 3K2S + 2H2O
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- Reaction of hydrogen sulfide and potassium arsenate
The reaction of hydrogen sulfide and potassium arsenate yields , arsenous acid, potassium sulfide, 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
- Reaction of hydrogen sulfide and potassium arsenate
General equation
- Reaction of reducing species and reducible species
- Reducing speciesReducing agent + Reducible speciesOxidizing agent ⟶ ProductOxidation product + ProductReduction product
Oxidation state of each atom
- Reaction of hydrogen sulfide and potassium arsenate
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| H2S | Hydrogen sulfide | 5 | Reducing | Reducing |
| K3AsO4 | Potassium arsenate | 2 | Oxidizing | Reducible |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| 2 | Oxidized | – | ||
| H3AsO3 | Arsenous acid | 2 | Reduced | – |
| K2S | Potassium sulfide | 3 | – | – |
| H2O | Water | 2 | – | – |
Thermodynamic changes
Changes in aqueous solution (1)
- Reaction of hydrogen sulfide and potassium arsenate◆
ΔrG −60.3 kJ/mol K 3.67 × 1010 pK −10.56
| 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 | 18.5 | −60.3 | 270 | – |
per 1 mol of | 3.70 | −12.1 | 54.0 | – |
per 1 mol of | 9.25 | −30.1 | 135 | – |
| 9.25 | −30.1 | 135 | – | |
per 1 mol of | 9.25 | −30.1 | 135 | – |
per 1 mol of | 6.17 | −20.1 | 90.0 | – |
per 1 mol of | 9.25 | −30.1 | 135 | – |
Changes in aqueous solution (2)
- Reaction of hydrogen sulfide and potassium arsenate
| 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 | 18.5 | – | – | – |
per 1 mol of | 3.70 | – | – | – |
per 1 mol of | 9.25 | – | – | – |
| 9.25 | – | – | – | |
per 1 mol of | 9.25 | – | – | – |
per 1 mol of | 6.17 | – | – | – |
per 1 mol of | 9.25 | – | – | – |
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 |
|---|---|---|---|---|
| H2S (g) | -20.63[1] | -33.56[1] | 205.79[1] | 34.23[1] |
| H2S (ao) | -39.7[1] | -27.83[1] | 121[1] | – |
| K3AsO4 (ai) | -1645.27[1] | -1498.23[1] | 144.8[1] | – |
* (g):Gas, (ao):Un-ionized aqueous solution, (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 |
|---|---|---|---|---|
| (cr) rhombic | 0[1] | 0[1] | 31.80[1] | 22.64[1] |
| (cr) monoclinic | 0.33[1] | – | – | – |
| (g) | 278.805[1] | 238.250[1] | 167.821[1] | 23.673[1] |
| H3AsO3 (ao) | -742.2[1] | -639.80[1] | 195.0[1] | – |
| H3AsO3 (aq) | -742.2[1] | – | – | – |
| K2S (cr) | -380.7[1] | -364.0[1] | 105[1] | – |
| K2S (ai) | -471.5[1] | -480.7[1] | 190.4[1] | – |
| K2S (cr) 2 hydrate | -975.3[1] | – | – | – |
| K2S (cr) 5 hydrate | -1871.5[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] |
* (cr):Crystalline solid, (g):Gas, (ao):Un-ionized aqueous solution, (aq):Aqueous solution, (ai):Ionized aqueous solution, (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°, -20.63 kJ · mol−1
- ^ ΔfG°, -33.56 kJ · mol−1
- ^ S°, 205.79 J · K−1 · mol−1
- ^ Cp°, 34.23 J · K−1 · mol−1
- ^ ΔfH°, -39.7 kJ · mol−1
- ^ ΔfG°, -27.83 kJ · mol−1
- ^ S°, 121. J · K−1 · mol−1
- ^ ΔfH°, -1645.27 kJ · mol−1
- ^ ΔfG°, -1498.23 kJ · mol−1
- ^ S°, 144.8 J · K−1 · mol−1
- ^ ΔfH°, 0 kJ · mol−1
- ^ ΔfG°, 0 kJ · mol−1
- ^ S°, 31.80 J · K−1 · mol−1
- ^ Cp°, 22.64 J · K−1 · mol−1
- ^ ΔfH°, 0.33 kJ · mol−1
- ^ ΔfH°, 278.805 kJ · mol−1
- ^ ΔfG°, 238.250 kJ · mol−1
- ^ S°, 167.821 J · K−1 · mol−1
- ^ Cp°, 23.673 J · K−1 · mol−1
- ^ ΔfH°, -742.2 kJ · mol−1
- ^ ΔfG°, -639.80 kJ · mol−1
- ^ S°, 195.0 J · K−1 · mol−1
- ^ ΔfH°, -742.2 kJ · mol−1
- ^ ΔfH°, -380.7 kJ · mol−1
- ^ ΔfG°, -364.0 kJ · mol−1
- ^ S°, 105. J · K−1 · mol−1
- ^ ΔfH°, -471.5 kJ · mol−1
- ^ ΔfG°, -480.7 kJ · mol−1
- ^ S°, 190.4 J · K−1 · mol−1
- ^ ΔfH°, -975.3 kJ · mol−1
- ^ ΔfH°, -1871.5 kJ · 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