I need assistance on this chem problem

[Equilibrium]

Which has a higher density, oxygen or air? Prove by calculations, knowing that air is approximately 20% oxygen and 80% nitrogen and that 1 mol of any gas occupies 22.4liters at STP

 

[Hootenanny]

Please read the following;

If you posted a question and it has gone unanswered, there are a few possible reasons:

1) Did you show your work? Homework helpers will not assist with any questions until you've shown your own effort on the problem. Remember, we help with homework, we don't do your homework. We already passed those classes; it's your turn to do so.

If you are seeking help with problems that are giving you some heartburn, then you have come to the right place!

But if you are looking for someone to do your homework for you, then you have come to the wrong place.

Please, for your own sake, try your homework before you come here, and show us where you got stuck. Speaking for myself and the other Mentors, Advisors, and Homework Helpers: We already know how to do your problem. Us doing it for you accomplishes nothing.

So, post away--and show your work!