## Cp or Cv??

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

Mariane Sanchez 1E
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

### Cp or Cv??

I'm still uncertain when to use Cv or Cp in finding the entropy. I've seen some threads saying that they will explicitly say which variable is constant in the question. But im looking at question 2part B on the winter 2014 Final where the volumes are changing, yet they still used Cv?

Tasnia Haider 1E
Posts: 55
Joined: Sat Jul 22, 2017 3:01 am

### Re: Cp or Cv??

If it is a sealed container, the final volume is always constant. It seems like volume is changing because there is a divider, but overall volume is not changing.