Enthalpy/ Internal Energy of Methane

[rotw]

Hello,

Could you please offer some help.

NIST isothermal online properties of Methane at 300 K and 10 MPa gives the following values

Internal Energy (kJ/mol) = 10.942
Enthalpy (kJ/mol) = 13.077

The software of NIST give the same above values.

Thermophysical properties of fluids given by this paper :

http://www.nist.gov/data/PDFfiles/jpcrd331.pdf

indicate on page 55 the following :

E (Internal Energy) (kJ/mol) = 6.436
H (Enthalpy) (kJ/mol) = 8.481

I am sure I am missing something but what?
can you please assist why above figures are different ?
Thanks a lot

 

[ione]

Have you checked the reference state is the same for both cases?

 

[25362]

Ione is absolutely right. Reference states differ. Besides, if Iread the tables correctly, the given E reading seems to be a typo, it should be 6.346 not 6.436 kJ/mol.

 

[rotw]

yes this is due to the reference states; you are perfectly right.

Thanks a lot guys.