When referring to the compilation of Henry's Law Constants, please cite
R. Sander: Compilation of Henry's law constants (version 4.0) for
water as solvent, Atmos. Chem. Phys., 15, 4399-4981 (2015),
Henry's law was formulated by the English chemist
William Henry in the early 19th century. It 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.
A compilation of 17350 Henry's law constants for 4632 organic and
inorganic species in water was collected from 689 references by
Sander (2015). Online access to
the searchable database is available here.
Symbols, definitions, and units
IUPAC recommends eight variants of Henry's law
(Sander et al., 2022):
Here, the Henry's law solubility constant
is used. It is defined as the ratio of the aqueous-phase concentration
of a chemical to its equilibrium partial pressure in the gas phase (at
To obtain other variants of the Henry's law constant, a
conversion tool is
available in the right column of this page.
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
- Values obtained under high pressures (p >> 1000 hPa) and
temperatures (T > 373 K) are not included.
Older (obsolete) versions of the compilation are also still available:
If you find errors or if you know of additional references that I could
include, please send me an email
at email@example.com. If you
have published measurements of Henry's law's constants, I would
appreciate it very much if you send me a pdf of your paper!
* * *
Search Henry's Law Database
* * *
Convert Henry's Law Constants
* * *