Amount concentration
\(c_{\rm{l}}\) of a species in the liquid phase divided by the amount concentration
\(c_{\rm{g}}\) of that species in the gas phase under equilibrium conditions at infinite dilution:
\[H_{\rm{s}}^{cc}: = \underset{c_{\rm{l}} \to 0}{\rm{lim}}\frac{c_{\rm{l}}}{c_{\rm{g}}}\]Note:
Instead of the amount concentrations \(c_{\rm{l}}\) and \(c_{\rm{g}}\), the mass concentrations \(\gamma_{\rm{l}}\) and \(\gamma_{\rm{g}}\) might be used here. This yields the same dimensionless Henry solubility because the molar mass \(\rm{M}\) of the solute cancels out:\(\gamma_{\rm{l}}/\gamma_{\rm{g}} = (c_{\rm{l}}M)/(c_{\rm{g}}M) = c_{\rm{l}}/c_{\rm{g}}\)
Example:
The dimensionless Henry solubility of ozone in water at \(T = \pu{298.15 K}\) is \(H_{\rm{s}}^{cc}(\ce{O3}) = 0.25\).
See: Henry’s law solubility constant
Source:
PAC, 2022, 94, 71. 'Henry’s law constants (IUPAC Recommendations 2021)' on page 74 (https://doi.org/10.1515/pac-2020-0302)