# hw4 - PHYS 333 Winter 2009 Assignment 4 Due 5:00 pm Friday...

This preview shows pages 1–2. Sign up to view the full content.

PHYS 333 Winter 2009 Assignment 4 Due: 5:00 pm Friday January 30 Most of these problems are from Schroeder’s book. 1. Entropy of Mixing. Calculate the increase in entropy when two different ideal gases diffuse into each other. The two gases are originally in separate containers, but with the same pressure and temperature. There are N A molecules of gas A, and N B molecules of gas B, with N = N A + N B , occupying volumes V A and V B respectively. After they have mixed, their volume is V = V A + V B . Do the calculation in three independent ways, and show, each time, that the answer is Δ S = k B N A ln [ N/N A ] + k B N B ln [ N/N B ] (a) Take the Sackur-Tetrode expression for the entropy, and calculate the change directly. (b) Schroeder, 2.38. Without using the S-T expression, show that the entropy change corre- sponding to mixing any two substances (think of two Einstein solids, for example) must be k B ln [ N ! /N A ! N B !]. Show that this is the same expression.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern