How does molecular weight affect the rate of diffusion?
1 Answer
At equal temperatures, lighter particles will diffuse more rapidly than heavier particles.
Explanation:
Diffusion is the movement of particles from where they are more concentrated to where they are less concentrated.
The average kinetic energy of a particle (KE) gives us the temperature of a substance.
KE =
If we have two gases (A and B) with gas A being heavier than B. The kinetic energy of the two gases will be the same if the gases are at the same temperature.
So at equal temperatures, a lighter particle (B) must have a greater velocity (speed) and a heavier particle (A) must have a lower speed.
Here is a video which gives further explanation of this topic. It discusses effusion, which is basically the diffusion of particles through a small opening in a container.
Hope this helps!
