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Henry's Law ConstantsRolf SanderThis page is obsolete, the new page is here: https://www.henrys-law.orgPlease update your bookmarks! (This page may still be available for a while, but it won't be updated anymore) |
Atmospheric Chemistry Division Max-Planck Institute for Chemistry |
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HomeHenry's Law ConstantsNotesReferencesErrataContact, Impressum, AcknowledgementsWhen referring to the compilation of Henry's Law Constants, please cite this publication: R. Sander: Compilation of Henry's law constants (version 4.0) for water as solvent, Atmos. Chem. Phys., 15, 4399-4981 (2015), doi:10.5194/acp-15-4399-2015 |
Scientific backgroundHenry's law states that the amount of dissolved gas is proportional to its partial pressure in the gas phase. The proportionality factor is called the Henry's law constant. It was formulated by the English chemist William Henry, who studied the topic in the early 19th century.The databaseA compilation of 17350 values of Henry's law constants for 4632 species, collected from 689 references, has been published by Sander (2015). Online access to the searchable database is available here.If you find errors or if you know of additional references that I could include, please send me an email at rolf.sander@mpic.de. Especially when you have published measurements of Henry's law's constants, I would appreciate it very much if you send me a reprint! What kind of data is included?The list contains Henry's law constants for several organic and inorganic species in water. The Henry's law constant is defined here as the ratio of the aqueous-phase concentration of a chemical to its equilibrium partial pressure in the gas phase.What kind of data is NOT included?Henry's law refers to small concentrations (lim c→0). Maximum solubilities are not included. Solubility products, i.e. products of ion concentrations are not included either.Henry's law constants for solvents other than water are not included. Values obtained under high pressures (p >> 1000 hPa) and temperatures (T > 373 K) are not included. Pressure or fugacity?The official IUPAC definition of Henry's law constants uses fugacity to describe the gas-phase composition. In my compilation, I use pressure. In other words, I am assuming a fugacity coefficient of 1. I think that this simplification is acceptable in environmental science where the partial pressures of trace gases are small. As mentioned above, values obtained under high pressures are not included in my list.Version HistoryOlder (obsolete) versions of the compilation are also still available: |
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