What are the differences between carbon dioxide solubility (miscibility, reaction) in liquid water when in gaseous ($\pu{<38 bar}$) and liquid ($>\pu{38 bar}$) phase? The temperature in my experiments is usually between $0$ and $\pu{5\!^\circ C}$. Is there more phase - interface for the reaction between water and $\ce{CO2}$ in the gaseous phase?
According to Henry's law for real gases (including a Poynting correction), the solubility should rise with the fugacity of the vapor. How is it however, when the carbon dioxide is liquid? When observing a pressure drop in a closed stirred vessel with liquid water and $\ce{CO2}$ on top of it, the pressure drop is much larger for gaseous $\ce{CO2}$ than for the liquid $\ce{CO2}$, this does not however imply a larger solubility? In my understanding it just means, that the liquid $\ce{CO2}$ is not that compressible and will mix in a different manner than gas and liquid water, resulting in a lower pressure drop.
