Diffusion Coefficient for two different gases (related to Fick's laws)
Description
Diffusion is the net movement of a substance (e.g., an atom, ion or molecule) from a region of high concentration to a region of low concentration. For two different gases, with different molecular masses and molecular diameters , the mean free path estimate of the diffusion coefficient:The diffusion coefficient “D” is the coefficient in the Fick’s first law and is related to the molecular masses, the molecular diameters and the conditions of pressure and temperatures (same for both gases).
Related formulasVariables
D | Diffusion coefficient (m2/s) |
kB | Boltzmann constant |
π | pi |
mA | Molecule mass of one of the two gases (kg) |
mB | Molecule mass of the other gas (kg) |
T | Absolute temperature (K) |
P | Pressure (Pa) |
dA | Molecule diameter of one of the two gases (m) |
dB | Molecule diameter of the other gas (m) |