Getting Real (Gassy)

Sorry, I couldn’t resist. Great class on Wednesday folks! I really appreciate how prepared all of you were, and thought you had some great discussions. Be sure that you understand the parts of the activity we didn’t get to during class.

The first two questions are, I think related:

1. “Can we actually define what compressibility is?”
2. “Is the assumption from KMT that gases have negligible volume valid?”

What is the root mean square velocity?

That’s a good question, and thanks for asking it! I know we briefly talked about this a little bit in class yesterday, but I wanted to put it here again. Who knows, maybe it will help you.

The kinetic molecular theory (KMT) of gases is based on the statistical distribution of molecular speeds at different temperatures. The statistical distribution for KMT is the Maxwell distribution of molecular speeds:

Just like any distribution, there are certain metrics that can be used to describe it. Some of these are quite familiar to you: