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Heat of Formation

DHf is heat of formation of the given substance from its elements.  All values of DHf are expressed as kcal/mole at 25°C.  Negative values of DHf indicate exothermic reactions.  s = solid, l = liquid, g = gas

Substance

Phase

DHf

Substance

Phase

DHf

aluminum oxide

s

-400.4

lead(II) nitrate

s

-108.0

ammonia

g

-11.02

lead(II) sulfate

s

-219.87

ammonium chloride

s

-75.15

lithium chloride

s

-97.58

ammonium sulfate

s

-282.23

lithium nitrate

s

-115.1

barium chloride

s

-205.1

lithium sulfate

s

-342.83

barium nitrate

s

-237.11

Magnesium chloride

aq

-190.46

barium sulfate

s

-352.1

magnesium chloride

s

-153.35

benzene

g

+19.82

magnesium oxide

s

-143.8

benzene

l

+11.71

magnesium sulfate

s

-307.1

calcium carbonate

s

-288.46

manganese (IV) oxide

s

-124.29

calcium chloride

s

-190.2

manganese (II) sulfate

s

-254.60

calcium hydroxide

s

-235.70

mercury(I) chloride

s

-63.39

calcium nitrate

s

-224.28

mercury(II) chloride

s

-53.6

calcium oxide

s

-151.80

mercury(II) fulminate

s

+64

calcium sulfate

s

-342.76

mercury(II) nitrate

s

-93.8

carbon (diamond)

s

0.45

mercury(II)oxide

s

-21.71

carbon (graphite)

s

0.00

methane

g

-17.89

carbon dioxide

g

-94.05

nitrogen dioxide

g

+7.93

carbon disulfide

g

+27.98

nitrogen monoxide

g

+21.57

carbon disulfide

l

+21.44

dinitrogen monoxide

g

+19.61

carbon monoxide

g

-26.42

dinitrogen pentoxide

g

+2.70

carbon tetrachloride

g

-22.90

dinitrogen pentoxide

s

-10.0

citric acid

aq

-329.34

dinitrogen tetroxide

g

+2.19

copper(II) nitrate

s

-72.4

oxygen (O2)

g

0.00

copper(II) oxide

s

-37.6

ozone (O3)

g

+34.1

copper(II) sulfate

s

-184.36

diphosphorus pentoxide

s

-713.2

copper(I) sulfide

s

-19.0

potassium bromide

s

-93.73

copper(II) sulfide

s

-12.7

potassium chloride

s

-104.18

ethane

g

-20.24

potassium hydroxide

s

-101.78

ethyne (acetylene)

g

+54.19

potassium iodide

s

-78.31

hydrogen (H2)

g

0.00

potassium nitrate

s

-117.76

hydrogen bromide

g

-8.71

potassium  sulfate

s

-342.66

hydrogen chloride

g

-22.06

silicon dioxide (quartz)

s

217.72

hydrogen chloride

aq

-40.02

silver acetate

s

-95.3

hydrogen fluoride

g

-64.80

silver chloride

s

-30.37

hydrogen iodide

g

+6.33

silver nitrate

s

-29.73

hydrogen oxide (water)

g

-57.80

silver sulfide

s

-7.79

hydrogen oxide (water)

l

-68.32

sodium bromide

s

-86.38

hydrogen peroxide

g

-32.53

sodium chloride

s

-98.23

hydrogen peroxide

l

-44.88

sodium hydroxide

s

-101.99

hydrogen sulfide

g

-4.82

sodium nitrate

s

-111.54

iodine (I2)

s

0.00

sodium sulfate

s

-330.90

iodine (I2)

g

+14.92

sulfur dioxide

g

-70.94

iron(III) chloride

s

-95.48

sulfur trioxide

g

-94.58

iron(III) oxide

s

-197.0

tin(IV) chloride

l

-122.2

iron(II,  III) oxide

s

-267.3

zinc chloride

aq

-116.68

iron(II) sulfate

s

-221.9

zinc nitrate

s

-115.6

iron(II) sulfide

s

-23.9

zinc oxide

s

-83.24

lead (II) oxide

s

-52.12

zinc sulfate

s

-234.9

lead(IV) oxide

s

-65.6

zinc sulfide

s

-49.23

 

Heat of Formation Table Illustrating Reactions for Heats of Formations

Formation Equation

Molecule Formed

DHf = kcal/mole

½ N2(g) + 3/2H2(g) àNH3(g)

ammonia

-11.0

6C(s)+3H2(g) à C6H6(l)

benzene

+11.72

4C(s)+ 5H2(g)à C4H10(g)

butane

-29.5

Ca(s)+C12(g)àCaC12(s)

calcium chloride

-190.0

Ca(s)+C(s)+ 3/2 O2(g)àCaCO3(s)

calcium carbonate

-288.5

Ca (s) + ½O2(g) à CaO(s)

calcium oxide

-151.9

Ca(s) + S(s) + 2O2(g)à CaSO4(s)

calcium sulfate

-342.4

C(s) + O2(g) à CO2(g)

carbon dioxide

-94.0

C(s) + ½O2(g) àCO(g)

carbon monoxide

-26.4

C(graphite)à C (diamond)

diamond

+0.45

2C(s) + 3 H2(g) à C2H6(g)

ethane

-20.2

2C(s) + 3H2(g) + ½ O2(g) à C2H5OH(l)

ethanol

-66.4

2C(s) + 2H2(g) à C2H4(g)

ethene

+12.5

2C(s) + H2(g) à C2H2(g)

ethyne

+54.2

½ H2(g) + ½ Cl2(g) à HCl(g)

hydrogen chloride

-22.1

½ H2(g) + ½I2(g) à HI(g)

hydrogen iodide

+6.2

Hg(l) + 2C(s) + N2(g) + 3/2 O2(g) à HgC2N2O3(s)

mercury fulminate

+64.10

C(s) +H2(g) + ½ O2(g) à CH2O(l)

methanal

-27.7

C(s) +2H2(g) à CH4(g)

methane

-17.9

H2(g) + C(s) + O2(g) à HCOOH(l)

methanoic acid

-97.8

1/2N2(g) + O2(g) à NO2(g)

nitrogen dioxide

+8.1

1/2N2(g) + ½ O2(g) à NO(g)

nitric oxide

 (nitrogen monoxide)

+21.6

8C(s) + 9H2(g) à C8H18(l)

octane

-49.8

3C(s) + 4H2(g) à C3H8 (g)

propane

-24.8

Na(s) + ½ Cl2(g) à NaCl(s)

sodium chloride

-98.2

S(s) + O2(g) à SO2(g)

sulfur dioxide

-71.0

S(s) +3/2 O2(g) à SO3(g)

sulfur trioxide

-94.5

H2(g) + S(s) + 2O2(g) à H2SO4(l)

sulfuric acid

-194.0

H2(g) +1/2 O2(g) à H2O(l)

water

-68.3

H2(g) +1/2 O2(g) à H2O(g)

water vapor

-57.8

  Reference Table from a Compilation of Tables long used at DCE

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November 16, 2013

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