# effect of adding an inert gas

#### aeriko

10+ Year Member
My question is the following: if we have a closed system (a container with fixed volume) filled with oxygen and we pump 80% argon and 20% oxygen at a constant rate while in the system there is also a small hole that allows some of the gas to leave the system,is this possible for the gases to separate with the argon being at the bottom of the container while the oxygen rests at the upper part of the container?

Thank you very much.

#### BlackSails

10+ Year Member
is this possible for the gases to separate with the argon being at the bottom of the container while the oxygen rests at the upper part of the container?
All gasses are completely miscible with each other in all proportions.

What you are looking for though is this: http://en.wikipedia.org/wiki/Graham's_law

OP
A

#### aeriko

10+ Year Member
Thank you very much!I didn't know about the law of effusion.

So, do you suggest that according to Graham's law,because the molar mass of argon is bigger of the oxygen, the oxygen will be diffused out of the container at a faster rate and argon will take all the place in the container,or not??

#### BlackSails

10+ Year Member
Thank you very much!I didn't know about the law of effusion.

So, do you suggest that according to Graham's law,because the molar mass of argon is bigger of the oxygen, the oxygen will be diffused out of the container at a faster rate and argon will take all the place in the container,or not??
Depending on what rate gas is pumped in, yes.

However, I dont understand how the rate of effusion is not concentration dependant.