Does air have mass? ```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. Try it out! topper Click here to return to the Chemistry Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs