# Homework Help: Working out the cp cv difference for van der waals equation

1. Feb 5, 2012

### imagemania

1. The problem statement, all variables and given/known data
I've put all the information on the picture as i already created on there in an attempt to help brain storm some ideas that didn't work ...

http://dl.dropbox.com/u/48169762/Capture.PNG [Broken]
2. Relevant equations

All on picture :)
http://dl.dropbox.com/u/48169762/Capture.PNG [Broken]

3. The attempt at a solution

Working out $\frac{\partial V}{\partial T}$ via its inverse first - but it didn't work (extremly messy given pressure substitutions etc.) - as explainedd on the picture.

Any guidence is much appreciated!

Last edited by a moderator: May 5, 2017
2. Feb 5, 2012

### imagemania

Ok, I've had another look at this problem and i'm still struggling, here's my idea:

[PLAIN]http://dl.dropbox.com/u/48169762/Capture3.PNG [Broken]

Last edited by a moderator: May 5, 2017