Table 3.
Reported stability constants and solubility constants of iron complexes with major water constituents. Reported values are at T = 25 °C and ionic strength 0.1 mol kg−1.
| Ligand | Reaction | logβ | References |
|---|---|---|---|
| Chloride | Fe2+ + Cl− → FeCl+ | 0.5 | [168,169] |
| Fe3+ + Cl− → FeCl2+ | 0.8 | ||
| Fe3+ + 2 Cl- → FeCl2+ | 1.0 | ||
| Phosphate | Fe3+ + H2PO4− → FeH2PO42+ | 3.5 | [170] |
| Fe3+ + HPO42− → FeHPO4+ | 8 | ||
| Sulfate | Fe3+ + SO42− → FeSO4+ | 2.3 | [149,168] |
| Fe3+ + 2 SO42− → Fe(SO4)2- | 3.2 | ||
| Carbonate | Fe3+ + 3 CO32− → Fe(CO3)33- | 22 | [149] |
| Fe(OH)2+ + CO32− → Fe(OH)(CO3)(aq) | 7.7 | ||
| Fe2+ + CO32− → FeCO3(s) | 10 (-logKsp) | ||
| Fulvic acid | Fe2+/3+ + fulvic acid → Fe-fulvic acid | 6 | [153] |
| Humic acid | Fe2+/3+ + humic acid → Fe-humic acid | 10 |