Henry’s law volatility constant (via p and w)

symbol: $H_{\rm{v}}^{pw}$, unit: $\pu{Pa}$

https://doi.org/10.1351/goldbook.09028

Partial pressure $p$ of a species in the gas phase divided by the mass fraction $w$ of that species in the liquid phase under equilibrium conditions at infinite dilution: \[H_{\rm{v}}^{pw}: = \underset{w \to 0}{\rm{lim}}\frac{p}{w}\]

Note:
The coherent SI unit for $H_{\rm{v}}^{pw}$ is $\pu{Pa}$.

Example:
The Henry volatility (defined via partial pressure and liquid-phase mass fraction) of ozone in water at $T = \pu{298.15 K}$ is $H_{\rm{v}}^{pw}(\ce{O3}) = \pu{2.1E8 Pa}$.

See also: Henry’s law volatility constant

Source:
PAC, 2022, 94, 71. 'Henry’s law constants (IUPAC Recommendations 2021)' on page 76 (https://doi.org/10.1515/pac-2020-0302)