Site pages
Current course
Participants
General
Topic 1
Topic 2
Topic 3
Topic 4
Topic 5
Topic 6
Topic 7
Topic 8
Topic 9
Topic 10
Topic 11
Topic 12
Topic 13
Topic 14
Topic 15
Topic 16
Topic 17
Topic 18
Topic 19
Topic 20
Topic 21
Topic 22
2.1.6. Gas diffusion
In the respiratory organ of animals gas diffuse between the environment and the organism; oxygen enters and carbondioxide leaves the animal. So it is important to know how fast the gases diffuse their rate of diffusion. The rate of diffusion of a gas is inverse by proportional to the square root of its molecular weight. $$Diffusion \ rate\ \alpha\ {1 \over sqrt{Molecular \ wt \ of \ gas}}$$
$$dQ\ =\ -DA{du \over dx}\ dt$$ Where Q = quantity of substance diffused A = Area through which diffusion takes place U = Concentration at the diffusion point x $$\{ {du \over dx}\ = \ concentration \}$$ D = Diffusion co efficient From this equation we can see that the amount of a substance diffusory is proportional to the elapsed time. The next consequence of fick’s equation is if the diffusion distance (x) is increased, the amount of the substance diffusing decreases. The diffusion over a constant concentration gradient is expressed by fick’s principle: |