Molar Enthalpy of Formation of Various Substances

Substance

Formula

M [kg/kmol]

hfo [kJ/kmol]
Carbon

C(s)

12.001

0

Hydrogen

H2(g)

2.016

0

Nitrogen

N2(g)

28.012

0

Oxygen

O2(g)

32

0

Carbon monoxide

CO(g)

28.013

-110,530

Carbon dioxide

CO2(g)

44.001

-393,520

Water Vapor

H2O(g)

18.016

-241,820

Water

H2O(l)

18.016

-285,820

Hydrogen peroxide

H2O2(g)

34.016

-136,310

Ammonia

NH3(g)

17.03

-46,190

Methane

CH4(g)

16.043

-74,850

Acetylene

C2H2(g)

26.038

226,730

Ethylene

C2H4(g)

24.034

52,280

Ethane

C2H6(g)

30.07

-84,680

Propylene

C3H6(g)

42.051

20,410

Propane

C3H8(g)

44.097

-103,850

n-Butane

C4H10(g)

58.123

-126,150

Benzene

C6H6(g)

78.114

82,930

n-Octane

C8H18(g)

114.231

-208,450

n-Octane

C8H18(l)

114.231

-249,950

n-Dodecane

C12H26(g)

170.22

-291,010

Methyl alcohol

CH3OH(g)

32.043

-200,670

Methyl alcohol

CH3OH(l)

32.043

-238,660

Ethyl alcohol

C2H5OH(g)

46.069

-235,310

Ethyl alcohol

C2H5OH(l)

46.069

-277,690

Oxygen

O(g)

16

249,190

Hydrogen

H(g)

1.008

218,000

Nitrogen

N(g)

14.006

472,650

Hydroxyl

OH(g)

17.008

39,460

Adapted from TEST (The Expert System for Thermodynamics) <www.thermofluids.net> by S.Bhattacharjee, San Diego State University

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Engineering Thermodynamics by Israel Urieli is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License