Hi, I have a practice problem in thermo that I have some difficulties with:

*The PVT relation for helium is given by the following equation of state:*

P=RT/V-b, where b=2.3*10^5 m^3/mol

Through an isenthalpic (H=0) throttling process, the gas is let to expand from a pressure of 10^8 Pa at 300 K to a pressure of 10^5 Pa. Calculate the final temperature of the gas. Cp canbe considered constant at a value of 5/2R.
I started by using the eq. for enthalpy

dH=0=CpdT + (V-T(dV/dT))dP and finding (dV/dT) from the PVT relation given which resulting in R/P

Replacing R/P in the dH eq. we get:

0=CpdT + (V-T(R/P))dP

Wouldn't this cancel the dP term since TR/P =V.

Or should I not cancel them and just integrate?

I'm a bit confused and could use some help.

Thank you in advance