Table 5 Thermodynamic data for the As-S system
From: Fate and transport of metals in H2S-rich waters at a treatment wetland
Source | Solid | T/°C | Reactions | Log K |
|---|---|---|---|---|
67 | Crystalline orpiment | 22 | As2S3 + 6H2O = 2H3AsO3°+ 3H2S | -25.8 |
68 | Crystalline orpiment | 22 | As2S3 + H2O = H2As2S3O° | -6.45 |
| Â | Â | Â | As2S3 + HS- = HAs2S4- | -1.47 |
| Â | Â | Â | As2S3 + OH- + HS- = As2S42- + H2O | +4.05 |
69 | Crystalline orpiment | 25 | 0.5As2S3 + 3H2O = H3AsO3°+ 1.5HS- + 1.5H+ | -23.11 |
| Â | Â | Â | 1.5As2S3 + 1.5HS- + 0.5H+ = H2As3S6- | + 3.61 |
70 | Amorphous As2S3 | 25 | 0.5As2S3 + 3H2O = H3AsO3°+ 1.5H2S° | -11.9 |
|  |  |  | 1.5As2S3 + 1.5H2S°= H2As3S6- + H+ | -5.0 |
71 | Amorphous As2S3 | 25 | 0.5As2S3 + 3H2O = H3AsO3°+ 1.5HS- + 1.5H+ | -22.38 |
| Â | Â | Â | 1.5As2S3 + 1.5HS- = As3S5(SH)2- + 0.5H+ | +1.78 |
|  |  |  | 1.5As2S3 + 1.5HS- = 1.5H+ = HAs3S4(SH)2° | +14.74 |