4HgI2 + 3e− → Hg22+ + 2[HgI4]2−
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- Reduction of mercury(II) iodide
Reduction of mercury(II) iodide yields dimercury(I) ion and tetraiodidomercurate(II) 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 mercury(II) iodide
General equation
- Reduction of reducible species
- ReactantOxidizing agent + e− ⟶ ProductReduction product
Oxidation state of each atom
- Reduction of mercury(II) iodide
Reactants
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| HgI2 | Mercury(II) iodide | 4 | Oxidizing | – |
| e− | Electron | 3 | – | Electron |
Products
| Chemical formula | Name | Coefficient | Type | Type in general equation |
|---|---|---|---|---|
| Hg22+ | Dimercury(I) ion | 1 | Reduced | – |
| [HgI4]2− | Tetraiodidomercurate(II) ion | 2 | – | – |
Thermodynamic changes
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 |
|---|---|---|---|---|
| HgI2 (cr) red | -105.4[1] | -101.7[1] | 180[1] | – |
| HgI2 (cr) yellow | -102.9[1] | – | – | – |
| HgI2 (g) | -17.2[1] | -59.9[1] | 336.13[1] | 61.09[1] |
| HgI2 (ao) | -79.5[1] | -75.3[1] | 176[1] | – |
| e− | – | – | – | – |
* (cr):Crystalline solid, (g):Gas, (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 |
|---|---|---|---|---|
| Hg22+ (ao) | 172.4[1] | 153.52[1] | 84.5[1] | – |
| [HgI4]2− | – | – | – | – |
* (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°, -105.4 kJ · mol−1
- ^ ΔfG°, -101.7 kJ · mol−1
- ^ S°, 180. J · K−1 · mol−1
- ^ ΔfH°, -102.9 kJ · mol−1
- ^ ΔfH°, -17.2 kJ · mol−1
- ^ ΔfG°, -59.9 kJ · mol−1
- ^ S°, 336.13 J · K−1 · mol−1
- ^ Cp°, 61.09 J · K−1 · mol−1
- ^ ΔfH°, -79.5 kJ · mol−1
- ^ ΔfG°, -75.3 kJ · mol−1
- ^ S°, 176. J · K−1 · mol−1
- ^ ΔfH°, 172.4 kJ · mol−1
- ^ ΔfG°, 153.52 kJ · mol−1
- ^ S°, 84.5 J · K−1 · mol−1