Gases Solved in Water - Diffusion Coefficients

Diffusion flux [kg/m²s] tells how fast a substanse solved in another substance flows due to concentration gradients. Diffusion constants [m²/s] for several gases in water.

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Fick's first law states that a substance will flow from region with high concentration to a region of low concentration. Fick's law can be expressed as

J = -D*dφ/dx [1]

where
J = diffusion flux - the amount of substance that flows through an unit area per unit time [mass or mol /(m²s)]
D = diffusion coefficient [m²/s]
dφ = change in concentration of substance [mass or mol/m³]
dx = change in length [m]

For simple one-dimensional transport, the diffusion coefficient describes the time–rate of change of concentration. The diffusion coefficient varies from substance to substance and with temperature.

See Water and Heavy Water - thermodynamic properties.
See also Water Boiling points at high pressure, Boiling points at vacuum pressure, Density, specific weight and thermal expansion coefficient, Dynamic and kinematic viscosity, Enthalpy and entropy, Heat of vaporization, Ionization Constant, pK_w, of normal and heavy water, Melting points at high pressure, Saturation pressure, Specific gravity, Specific heat (heat capacity) and Specific volume for online calculatores, and similar figures and tables as shown below, as well as Air - Diffusion Coefficients of Gases in Excess of Air

Diffusion coeff noble gases water temp C

Diff coeff gas air temperature C

Diffusion coefficients for some common gases in water:
(Gas–liquid diffusion coefficients are difficult to measure, and since the values below are from different sources and different measuring methods, there is some uncertainty about the values)

Gas in water		Diffusion coefficient, D, [x10^-5 cm²/s ] at atmospheric pressure and given temperatures
Gas in water		10 °C	15 °C	20 °C	25 °C	30 °C	35 °C
Name	Formula	50 °F	59 °F	68 °F	77 °F	86 °F	95 °F
Acetylene	C2H2	1.43	1.59	1.78	1.99	2.23
Ammonia	NH3		1.30	1.50
Argon	Ar				2.50
Bromomethane	CH3Br				1.35
Carbon dioxide	CO2	1.26	1.45	1.67	1.91	2.17	2.47
Chlorine	Cl2		1.13	1.50	1.89
Chloromethane	CH3Cl				1.40
Dichlorofluorumethane	CHCl2F				1.80
Helium	He	5.67	6.18	6.71	7.28	7.87	8.48
Hydrogen	H2	3.62	4.08	4.58	5.11	5.69	6.31
Hydrogen bromide	HBr				3.15
Hydrogen chloride	HCl				3.07
Hydrogen sulfide	H2S				1.36
Krypton	Kr	1.20	1.39	1.60	1.84	2.11	2.40
Methane	CH4	1.24	1.43	1.62	1.84	2.08	2.35
Neon	Ne	2.93	3.27	3.64	4.03	4.45	4.89
Nitrogen	N2				2.00
Nitrogen dioxide	NO2			1.23	1.40	1.59
Nitrous oxide	N2O		1.62	2.11	2.57
Oxygen	O2		1.67	2.01	2.42
Radon	Rn	0.81	0.96	1.13	1.33	1.55	1.80
Sulfur dioxide	SO2			1.62	1.83	2.07	2.32
Xenon	Xe	0.93	1.08	1.27	1.47	1.70	1.95