[deardirestraits]

I'm a teacher looking for a deeper understanding of the mole.

How is a mole experimentally measured quantitatively?  Where do we get 6.02 x 10^23?

How do we know a mole occupies 22.4L at STP?  Does this volume only hold true for gasses that actually exist as gasses at STP? 

[Borek]

How is a mole experimentally measured quantitatively?  Where do we get 6.02 x 10^23?

http://en.wikipedia.org/wiki/Mole_(unit)

Or do you mean how do we determine value of Avogadro number?

How do we know a mole occupies 22.4L at STP?  Does this volume only hold true for gasses that actually exist as gasses at STP?  

What do you mean by gasses that exist as gasses?

But it is basically PV=nRT and R is determined experimentally.