Name: mark s scheiber
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: 1999

Question:
Does air have mass?

Replies:
Yes, it does. It just isn't very dense, so there
isn't as much matter in a cup of air as there is
in a cup of water. However, it does have mass,
and you can calculate it. Let's say I have
1 liter of air at 1 atm of pressure and at 25 degrees Celsius
(298K). I can use the equation PV = nRT (the gas law)
to calculate n, the number of moles of air, given
that R is a constant equal to 0.0821. Now, if you assume
that about 70% of those moles are nitrogen gas (weighing
28 grams per mole) and 30% are oxygen (weighing 32 grams per mole)
you can estimate how many grams of air you would have.

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