Gas | −log K
H
| −∆Hr (kJ/mol) |
D
w
(10−9 m2/s) |
D
e
(10−11 m2/s) |
|---|
H2O | −1.506 | −44.03 | 2.24 | 3.54 |
H2
| 3.10 | (Polynomial) | 5.13 | 8.12 |
He | 3.41 | (Polynomial) | 7.29 | 11.53 |
N2
| 3.19 | (Polynomial) | 1.96 | 3.10 |
Ne | 3.35 | (Polynomial) | 4.04 | 6.39 |
Ar | 2.86 | (Polynomial) | 2.45 | 3.88 |
CO2
| 1.468 | (Polynomial) | 1.92 | 3.04 |
CH4
| 2.85 | (Polynomial) | 1.85 | 2.93 |
C2H6
| 2.69 | −19.5 | 1.53 | 2.42 |
C3H8
| 2.85 | −22.2 | 1.29 | 2.04 |
- The solubilities (Scharlin et al. 1998) and diffusion coefficients in pure water (Dw) are for 25 °C; value for HTO in water comes from Mills and Harris (1976); values for the gases N2, Ar, CH4 and CO2 were taken from Table 4.4 in Boudreau (1997) and stem from Jähne et al. (1987) and Ohsumi and Horibe (1984). Values for the gases C2H6 and C3H8 come from Hayduk and Laudie (1974) and (Table 4.3 in Boudreau 1997), but multiplied by 1.1 to be commensurate with the higher diffusion coefficient for CH4 given by Jähne et al. (1987) compared with Hayduk and Laudie (1974); in the model, solubilities are corrected to 15.6 °C using Van’t Hoff’s equation with the dissolution reaction enthalpy (ΔHr) or with a polynomial; effective diffusion coefficients (De) are corrected by accounting for the viscosity change of water with temperature at 15.6 °C
