Table 1.
Basic physicochemical and thermodynamic properties of H2S. Reprinted with permission from Ref. [5]. Copyright ©2018 American Chemical Society.
| Properties | Data |
|---|---|
| Dipole moment | 0.97 D |
| Solubility (in H2O) | 110 mM/atm, 25 °C |
| 210 mM/atm, 0 °C | |
| Boiling temperature | −60.2 °C |
| Density (25 °C, 1 atm) | 1.36 kg/m3 |
| IR | ν1 2525, 2536 cm−1 |
| ν2 1169, 1184, 1189 cm−1 | |
| ν3 2548 cm−1 | |
| 1H-NMR | 0.52 ppm |
| pK1 | 6.98 |
| pK2 | >17 at 25 °C |
| λmax (HS−) | 230 nm |
| ε | 8 × 103 M−1·cm−1 |
| Henry’s law coefficient (298 K) | 0.087135 mol solute/mol water atom |
| Detection threshold by human nose | 0.02–0.03 ppm |
| Lethal dose | >500 ppm |
| ΔfG° (H2S) | −28 kJ/mol |
| ΔfG° (HS−) | +12 kJ/mol |
| ΔfG° (S2−) | +86 kJ/mol |
| E°′ (S•−, H+/HS−) | +0.91 V |
| E°′ (HS2−, H+/2HS−) | −0.23 V |