Calculating isothermal copressibility and expansion coefficient

1. Sep 19, 2009

Zcuttlefish

1. The problem statement, all variables and given/known data
Calculate the isothermal compressibility and the expansion coefficient of a van der waals gas. Then show using Euler's chain relation that KR = alpha(Vm-b)

2. Relevant equations
isothermal compressibility K = (-1/V) (dv/dp)t
isothermal expansion alpha= (1/v)(dv/dt)p

3. The attempt at a solution
I realize it has to do with partial derivatives. But beyond this i'm lost.

2. Sep 19, 2009

gabbagabbahey

Hi Zcuttlefish, welcome to PF!

Hint: You might start by looking up the equation of state for a Van Der Waals gas!

3. Sep 19, 2009

Zcuttlefish

I did (p+ a/V2)(v-b) = RT
(not including n because it should be constant)

my answer for dv/dp ended up looking like
Then i used the product rule and took the derivative dv/dp of the terms. I'm still unsure of why or if i've even gotten closer to the answer.

V3(v-b)/(2a(v-b)2-RTV3)
I seem to be missing an R on top.