Henry's Law Constants (Solubilities)


Table of contents

1) Introduction

Calculations in atmospheric chemistry depend strongly on the availability of kinetic and thermodynamic data. For gas-phase chemistry, evaluations such as the IUPAC or JPL data sets greatly facilitate obtaining reliable values. However, there has been no such comprehensive compilation for Henry's law constants (solubilities) for tropospheric modeling of clouds and aerosol particles. Waste water treatment is another research area where Henry's law constants are needed since solubility affects volatilization of toxic compounds into the air. I have gathered data from different sources. The Henry's law constants, which can (unfortunately) be defined in several ways and expressed using different units, have been converted into a uniform format (unit: mol m-3 Pa-1).

2) Download

The current version (582 pages) is available here:

R. Sander
Compilation of Henry's law constants (version 4.0) for water as solvent
Atmos. Chem. Phys., 15, 4399-4981, 2015

If you would like to order a printed copy of the article, please contact the Copernicus publisher at production@copernicus.org.

Older (obsolete) versions are also still available:

3) Frequently asked questions

What kind of data is included in the list?

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 in the list?

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.

Why are CO and CO2 apparently not included?

You cannot find them in the inorganic section. CO and CO2 are included in the miscellaneous organics subsection (all species containing carbon atoms are in the organic section).

Can you help me? I've got a question!

You're welcome to send me an email but please don't be too disappointed in case I don't have the time to answer it. Collecting Henry's law constants is not my main job. It's just something I did because I needed (and still need) them for my research. I have received much more email than I expected and I won't be able to answer all questions individually. Before sending me an email, please consider the following points:

Converting between different definitions and units for Henry's law constants can be quite tricky. I'm afraid I won't have the time to answer individual questions on how to convert from unit xxx to unit yyy.

Henry's law constants are used in several research areas, e.g. pesticide control, waste water management, and atmospheric chemistry. Since I'm an atmospheric chemist myself, I don't think I will be able to help you with problems in the other research areas.

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. This simplification is justified in environmental science where pressure is around 1 atmosphere. As mentioned above, values obtained under high pressures are not included in my list.

4) Errata

Well, I knew it would happen... A big list like this just couldn't be perfect. I have now added a list of errors that I have made in my compilation.

Errata for version 4.0

If you notice that any Henry's law data (e.g., from your work) are missing or incorrectly listed, please send an email to rolf.sander@mpic.de.

Errata for version 3.99

Errata for version 3

5) Bug reports and comments

If you find errors in the list 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! If you have any other comments or questions, please read the 'frequently asked questions' first (see above)!!!
Rolf Sander This document was last changed 10 Aug 2015