Molality
\(b\) of a species divided by the partial pressure
\(p\) of that species in the gas phase under equilibrium conditions at infinite dilution:
\[H_{\rm{s}}^{bp}: = \underset{b \to 0}{\rm{lim}}\frac{b}{p}\]Notes: - The coherent SI unit for \(H_{\rm{s}}^{bp}\) is \(\pu{mol m-3 Pa-1}\).
- Here, the symbol \(b\) is used for molality (instead of \(m\)) to avoid confusion with the symbol \(m\) for mass.
- Molality refers to the mass of solvent and should not be confused with content which refers to the mass of solution.
Example:
The Henry solubility of ozone in water at \(T = \pu{298.15 K}\) is \(H_{\rm{s}}^{bp}(\ce{O3}) = \pu{1.0E-7 mol kg-1 Pa-1}\).
See also: Henry’s law solubility constant
Source:
PAC, 2022, 94, 71. 'Henry’s law constants (IUPAC Recommendations 2021)' on page 76 (https://doi.org/10.1515/pac-2020-0302)