[burntbread07]

EDIT:  I thought I posted this on the wrong forum but I didn't, lol.  Sorry, and here's my question again.

I've been working on this problem for a while:
Calculate the isothermal compressibility and the expansion coefficient of a van der Waals gas.  Show, using Euler's chain relation that

K_TR=alpha(V_m-b)

I know that compressibility for an ideal gas is K_T=(-1/V)*(dV/dP)_T <---that's a partial derivative
K_T=(-1/V)*(-nRT/P²)=1/P

and the expansion coefficient alpha=(1/V)*(dV/dT)_P

I took the derivative of the Van der Waals eq. and got P(dV/dT)_P-(a/V²)(dV/dT)_P+(2ab/V³)(dV/dT)_P=R

From there I can get an expression for (dV/dT)_P but I don't know where to go from here.  It bears some resemblance to the virial equation pV=RT(1+(B/V)+(C/V^2)+...)

Any ideas on what I should try or what would help?

Thanks