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Linda Joyce
Rocky Mountain Research Station
240 West Prospect
Fort Collins, CO 80526
Phone: 970-498-2560
ljoyce@fs.fed.us
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Coefficients of molecular diffusivity

Recommended coefficients of diffusivity (cm2 / s) of selected gases in air, N2, and O2.  Only D (0,1) is given, D(T,p) = D(0,1)(p0/p)(T/T0)1.81 is assumed.
 
Gas Air N2 O2
H2O 0.2178 0.2178 0.2178
CO2 0.1381 0.1429 0.1402
CH4 0.1952 0.1892 0.1942
CO* 0.1807** 0.1804 0.1817
SO2 0.1119S 0.1089 0.1089
O3 0.1444 0.1441 0.1454
NH3 0.1978 0.1978 0.1992
N2O 0.1436 0.1402 0.1396
NO 0.1802 0.1809 0.1815
NO2 0.1361 0.1359 0.1369
N2* 0.1788** 0.1783 0.1809
O2 0.1820** 0.1809 0.1862
Hg vapor 0.1194 0.1211 0.1227
O 0.2773 0.2773 0.2773
OH 0.2543 0.2527 0.2604
H2SO4 0.0752 0.0762 0.0717
HNO3 0.1041 0.1075 0.1041
HNO2 (HONO) 0.1349 0.1354 0.1331
H2O2 0.1300 0.1300 0.1300
NO3 0.1153 0.1160 0.1125
N2O5 0.0808 0.0816 0.0777


*Isometric molecules 
** From Blanc's law  and D(0,1) for gas in N2 and in O2
S - recalculated with new data
 
   - Numbers are not final

Recommended Thermal Diffusivity and kinematic viscosity  (cm2/s) of air (cm2/s). Only k(0, 1) and v(0, 1) are given by k(T, p) = k(0, 1)(p0/p)(T/T0)1.81 and v(T,p)=v(0,1)(p0/p)(T/T0)1.81 are assumed k(0, 1) = 0.1869 and v(0, 1) = 0.1327.


Publications for more details on these figures:
A review of the molecular diffusivities of H2O, CO2, CH4, CO, O3, SO2, NH2, N2O, NO and NO2 in air, O2 and N2 near STP. Atmospheric Environment, 32A 1111-1127.  1998. Massman, WJ.
Molecular diffusivities of Hg vapor in air, O2 and N2 near STP and the kinematic viscosity and thermal diffusivity of air near STP. Atmospheric Environment, 33, 453-457.  1999. Massman, WJ.
 
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