SI Units           English Units
 
 
Enthalpy of formation, Gibbs function of formation, and absolute entropy at 250C, 1atm
   
 
Substance Formula kJ/kmol kJ/kmol kJ/kmol*K
Carbon C(s) 0 0 5.74
Hydrogen H2(g) 0 0 130.68
Nitrogen N2(g) 0 0 191.61
Oxygen O2(g) 0 0 205.04
Carbon monoxide CO(g) -110,530 -137,150 197.65
Carbon dioxide CO2(g) -393,520 -394,360 213.80
Water Vapor H20(g) -241,820 -228,590 188.83
Water   H20(l) -285,830 -237,180 69.92
Hydrogen peroxide H2O2(g) -136,310 -105,600 232.63
Ammonia NH3(g) -46,190 -16,590 192.33
Methane CH4(g) -74,850 -50,790 186.16
Acetylene C2H2(g) 226,730 209,170 200.85
Ethylene C2H4(g) 52,280 68,120 219.83
Ethane C2H6(g) -84,680 -32,890 229.49
Propylene C3H6(g) 20,410 62,720 266.94
Propane C3H8(g) -103,850 -23,490 269.91
n-Butane C4H10(g) -126,150 -15,710 310.12
n-Octane C8H18(g) -208,450 16,530 466.73
n-Octane C8H18(l) -249,950 6,610 360.79
n-Dodecane C12H26(g) -291,010 50,150 622.83
Benzene C6H6(g) 82,930 129,660 269.2
Methyl alcohol CH3OH(g) -200,670 -162,000 239.7
Methyl alcohol CH3OH(l) -238,660 -166,360 126.8
Ethyl alcohol C2H5OH(g) -235,310 -168,570 282.59
Ethyl alcohol C2H5OH(l) -277,690 -174,890 160.7
Oxygen O(g) 249,190 231,770 161.06
Hydrogen H(g) 218,000 203,290 114.72
Nitrogen N(g) 472,650 455,510 153.3
Hydroxyl OH(g) 39,460 34,280 183.7