Standardized Enthalpies and Entropies

Standardized enthalpies and entropies for common substances at 25°C (77°F) and 1 atm. Reference data includes entropy and enthalpy values in both imperial (Btu/lbmole) and SI (J/gmole) units.

Substance	Entropy - s - (Btu/lbmole·R)	Entropy - s - (J/gmole·K)	Enthalpy - h - (Btu/lbmole)	Enthalpy - h - (J/gmole)
Acetylene C2H2	47.97	200.82	97495	226757
Benzene C6H6	64.3	269.21	35653	82923
n-Butane C4H10	74.1	310.03	-53627	-124727
Carbon Dioxide CO2	51.03	213.66	-169183	-393492
Carbon Monoxide CO	47.3	197.92	-47517	-110516
Ethane C2H6	54.8	229.48	-36401	-84662
Hydrogen H2	31.2	130.6	0	0
Methane CH4	44.5	186.19	-32179	-74843
Nitrogen N2	45.8	191.56	0	0
Oxygen O2	48.99	205.09	0	0
Propane C3H8	64.47	269.92	-44647	-103848
Water H2O	16.72	70	-122976	-286022