[vivekrai]

There are two containers 'I' and 'II' having equal P,V,T. 'I'  contains 5 moles of Nitrogen and 'II' contains 3 moles of Oxygen and 2 moles of Helium. Find the ratio of rate of effusion of The gas in 'I' to the gaseous mixture in 'II'.

If I use here for M(mix) = (n1m1+n2m2)/(n1+n2) will it give correct answer?

[vivekrai]

  Any suggestions Please?

[Borek]

If you mean using weighted average for the molar mass of the mixture - yes, that looks like a reasonable approach to me.

[vivekrai]

Okay. Certainly this would gives us the rate which is equal for the effusion of the gas in I to mixture in II. However, If we try to imagine the gases issuing out of the mixture II, certainly Oxygen and Helium won't be in the same ratio (I mean if after sometime, we close the holes, the ratio of the gases in the mixture won't remain same as it was before i..e, 3:2).

So, How do we work out to investigate what is the relative rate of effusion of the gases contained in the mixture II itself or determine what will be left after certain time?