Thermal and chemical properties of commonly used substances

Thermodynamics

| May 6, 2022, 5:41 p.m.

Table below will provide approximate values of molar mass, enthalpy of formation, gibbs function of formation, higher and lower heating value and absolute entropy for some commonly used substances.

Please note that all the values shown below are at 298K temperature and 1 atm pressure.

Substance

Molar mass(g/mol)

Enthalpy of formation(kJ/mol)

Absolute entropy (kJ/molK)

Gibbs function of formation (kJ/mol)

Lower heating value (MJ/kg)

Higher heating value (MJ/kg)

Carbon(s)

12

0

0.006

0

33

33

Oxygen(g)

32

0

0.20

0

-

-

Carbon monoxide(g)

28

-110.5

0.198

-137.2

-

-

Carbon dioxide(g)

44

-393.5

0.214

-394.4

-

-

Hydrogen(g)

2

0

0.13

0

120

142

Nitrogen(g)

28

0

0.192

0

-

-

Water(g)

18

-241.8

0.189

-228.6

-

-

Water(l)

18

-285.8

0.07

-237.1

-

-

Ammonia(g)

17

-46.2

0.192

-16.5

-

-

Hydrogen peroxide(g)

34

-136.3

0.233

-105.7

-

-

Benzene(g)

78

82.9

0.269

129.7

40.5

42.2

Methyl alcohol(g)

32

-200.9

0.239

-162.1

21.2

23.9

Methyl alcohol(l)

32

-238.8

0.129

-166.2

20

22.8

Ethyl alcohol(g)

46

-235.3

0.282

-168.5

27.8

30.6

Ethyl alcohol(l)

46

-277.7

0.160

-174.9

26.7

29.7

Propylene(g)

42

20.4

0.267

62.7

45.8

49

Propane(g)

44

-103.8

0.269

-23.5

46.5

50.3

Butane(g)

58

-126.1

0.310

-15.7

46

49.8

Pentane(g)

72

-146.4

0.348

-8.2

45.4

49

Octane(g)

114

-208.5

0.464

17.3

44.8

48.4

Octane(l)

114

-250

0.360

6.6

44.4

48

Ethylene(g)

28

52.3

0.220

68.1

47.2

50.4

Ethane(g)

30

84.7

0.230

-32.9

47.3

51.6

Methane(g)

16

-75

0.186

-50.8

50

55

Acetylene(g)

26

226.7

0.201

209.2

48.2

50

Hydroxyl(g)

17

39.5

0.184

34.3

-

-