How Is the Joule-Thomson Coefficient Calculated Without Knowing Volume?

[alexandria7]

Hi. I need a little help with this question. I found a useful link below but can't figure out how to find the joule-thomson coefficient without knowing volume. I'd appreciate any pointers on this. Thanks.

http://www.ccr.buffalo.edu/etomica/app/modules/sites/JouleThomson/Background3.html

Steam at 12 MPa and 450 oC is throttled in a valve to a pressure of 5 MPa in a steady flow process. Determine:

-the new temperature of the steam
-the entropy generation for the process and check if the second law is satisfied

Steam table:

P (Mpa) T (oC) h (kJ kg-1) s (J g-1 K-1)
12.0 450.00 3209.8 6.3028
5.0 350.00 3069.3 6.4516
5.0 360.00 3095.6 6.4935
5.0 370.00 3121.5 6.5340
5.0 380.00 3146.9 6.5732
5.0 390.00 3171.9 6.6112
5.0 400.00 3196.7 6.6483
5.0 410.00 3221.2 6.6844
5.0 420.00 3245.4 6.7196

 

[Astronuc]

One can use specific volume, which one can look up in the appropriate table, as one has found specific enthaply and specific entropy.