# This thermodynamic quantity equals what?

1. Mar 30, 2014

### M. next

I am trying to use thermodynamics manipulations in order to find $\partial$P/$\partial$V (at constant entropy) I tried replacing P by T($\partial$S/$\partial$V)(at constant Energy) and then differentiated that by V but didn't help me. Do you have any idea where I can get around with this? Just throw in any formula!

Thanks!

2. Apr 1, 2014

### rude man

Well, there's ks = adiabatic compressibility (= reciprocal of the adiabatic bulk modulus):

ks = - (1/v)(∂v/∂p)|s,
s = sp. entropy.

It's related to Cp/CV = γ = k/ks

where k = the reciprocal of the isothermal bulk modulus = (-1/v)(∂v/∂p)|T.