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

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

synonym: Henry volatility (defined via partial pressure and liquid-phase amount fraction)

https://doi.org/10.1351/goldbook.09027

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

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

Example:
The Henry volatility (defined via partial pressure and liquid-phase amount fraction) of ozone in water at $T = \pu{298.15 K}$ is $H_{\rm{v}}^{px}(\ce{O3}) = \pu{5.5E8 Pa}$.

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)