A list of substances and related enthalpies that can be used for Hess's Law calculations.

1. C06 Enthalpy Table
Standard Heats of Formation, ΔHformation
Hess’s Law, ΔHrx = ΣΔHformation products - ΣΔHformation reactants
Standard Enthalpy of
Formation Table
ΔHformation
Substance kJ/mol
Al(s) 0
Al2O3(s) -1670
C(s, graphite) 0
CO (g) -111
CO2 (g) -394
CH4 (g) -75
CH3OH (l) -239
C2H2 (g) 227
C2H4 (g) 52
C2H6 (g) -85
C2H5OH (l) -278
CaO (s) -636
Ca(OH)2 (s) -987
CaSO4(s) -1433
Cl2 (g) 0
Fe2O3 (s) -822
H2 (g) 0
HCl(g) -92
H2O (g) -242
H2O (l) -286
H2O2 (l) -188
H2SO4 (l) -811
Hg (l) 0
Hg (g) 61
MgO(s) -602
N2 (g) 0
NH3 (g) -46
NH4Cl(s) -315
N2O (g) 82
N2O4 (g) 10
NaCl (s) -411
NaOH (s) -427
O2 (g) 0
P4O10(s) -2980
S(s) 0
SO2 (g) -297
SO3 (g) -395