Graham's Law of Diffusion

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Graham's Law of Diffusion
The relative rates at which two gases under identical conditions of temperature and pressure will diffuse vary inversely as the square roots of the molecular masses of the gases.

Assume following temperature conditions for two different gases:
T1 = T2
and by this that these two gases has the same kinetic energy (Ek=1/2mv2)
1/2m1v12 = 1/2m2v22
Moving v2 to the left and m1 to the right side of the equation we get:
v12/v22 = m2/m1
Taking the square root we get:
v1/v2 = (m2/m1)1/2

If we know the mass/density and the velocity of a gas, also knowing the mass/density or the velocity of a second gas, we should be able to calculate the velocity or mass/density of the second gas.

Graham's Law of Diffusion
  Equal amounts of Argon and Helium was placed in a porous container and allowed to escape. Which gas will escape faster ?
Answer: Helium will escape 3.16 times faster tan Argon

grahams law of diffusion

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