Standard Enthalpy of Formation

Searchable database of ΔHf° values for 180+ compounds.

Search Standard Enthalpies of Formation

Showing 272 of 272 compounds

State
(CH3)2CO(l)Acetonel-248.10
(NH4)2SO4(s)Ammonium sulfates-1180.85
Ac2O3(s)Actinium oxides-1756.00
Ag2O(s)Silver oxides-31.05
Ag2SO4(s)Silver sulfates-715.90
AgCl(s)Silver chlorides-127.01
AgNO3(s)Silver nitrates-124.40
Al(s)Aluminums0.00
Al2O3(s)Aluminum oxides-1675.70
AlCl3(s)Aluminum chlorides-704.20
AmO2(s)Americium dioxides-932.00
Ar(g)Argong0.00
As2O3(s)Arsenic trioxides-624.70
As4(s)Arsenics0.00
AsH3(g)Arsineg66.40
At2(s)Astatines0.00
AuCl3(s)Gold(III) chlorides-117.60
B2H6(g)Diboraneg35.40
B2O3(s)Boron oxides-1272.77
BaCl2(s)Barium chlorides-858.60
BaO(s)Barium oxides-553.50
BaSO4(s)Barium sulfates-1473.20
BCl3(g)Boron trichlorideg-403.80
BeCl2(s)Beryllium chlorides-490.40
BeO(s)Beryllium oxides-609.60
BF3(g)Boron trifluorideg-1136.00
BhO3(s)Bohrium trioxides-400.00
Bi2O3(s)Bismuth trioxides-573.90
Br2(l)Bromine (liquid)l0.00
C(s,diamond)Carbon (diamond)s1.89
C(s,graphite)Carbon (graphite)s0.00
C12H22O11(s)Sucroses-2226.10
C2Cl2F4(g)Dichlorotetrafluoroethane (R-114)g-938.00
C2H2(g)Acetyleneg226.73
C2H2F4(g)Tetrafluoroethane (R-134a)g-1012.00
C2H3Cl3(l)Trichloroethanel-215.00
C2H4(g)Ethyleneg52.26
C2H4Cl2(l)Dichloroethanel-165.00
C2H4O(g)Ethylene oxideg-52.63
C2H4O2(l)Acetic acid (alt)l-484.50
C2H5OH(l)Ethanoll-277.69
C2H6(g)Ethaneg-84.68
C2H6O(l)Dimethyl etherl-184.10
C2H6S(l)Dimethyl sulfidel-65.40
C3H8(g)Propaneg-103.85
C3H8O(l)Isopropanoll-318.10
C4H10(g)Butaneg-126.15
C4H10(l)Butane (liquid)l-147.30
C4H4S(l)Thiophenel80.60
C5H12(l)Pentanel-173.50
C6H12(l)Cyclohexanel-156.40
C6H12O6(s)Glucoses-1273.30
C6H14(l)Hexanel-198.70
C6H5Cl(l)Chlorobenzenel51.80
C6H5NH2(l)Anilinel31.10
C6H5NO2(l)Nitrobenzenel12.50
C6H5OH(s)Phenols-165.02
C6H6(l)Benzenel49.04
C7H16(l)Heptanel-224.40
C7H8(l)Toluenel12.00
C8H10(l)Xylenel-24.40
C8H18(l)Octanel-250.10
Ca(OH)2(s)Calcium hydroxides-986.09
Ca(s)Calciums0.00
CaCl2(s)Calcium chlorides-795.80
CaCO3(s)Calcium carbonates-1206.92
CaO(s)Calcium oxides-635.09
CaSO4(s)Calcium sulfates-1434.11
CCl2F2(g)Dichlorodifluoromethane (R-12)g-477.00
CCl3F(g)Trichlorofluoromethane (R-11)g-284.00
CCl4(l)Carbon tetrachloridel-135.40
CeO2(s)Cerium dioxides-1088.70
Cf2O3(s)Californium oxides-1653.00
CH2Cl2(l)Dichloromethanel-124.20
CH2F2(g)Difluoromethane (R-32)g-452.00
CH2O(g)Formaldehydeg-108.57
CH3CHO(g)Acetaldehydeg-166.19
CH3COOH(l)Acetic acidl-484.50
CH3OH(l)Methanoll-238.70
CH4(g)Methaneg-74.81
CHCl3(l)Chloroforml-134.10
CHClF2(g)Chlorodifluoromethane (R-22)g-475.00
CHF3(g)Fluoroform (R-23)g-697.00
Cl2(g)Chlorineg0.00
Cm2O3(s)Curium oxides-1682.00
Cn(s)Coperniciums0.00
CO(g)Carbon monoxideg-110.53
CO2(g)Carbon dioxideg-393.51
Co3O4(s)Cobalt(II,III) oxides-891.00
CoO(s)Cobalt(II) oxides-237.90
COS(g)Carbonyl sulfideg-137.20
Cr2O3(s)Chromium(III) oxides-1139.70
CrO3(s)Chromium trioxides-589.50
CS2(l)Carbon disulfidel89.41
CsCl(s)Cesium chlorides-433.00
Cu(s)Coppers0.00
Cu2O(s)Copper(I) oxides-168.60
CuO(s)Copper(II) oxides-157.30
CuSO4·5H2O(s)Copper(II) sulfate pentahydrates-2279.65
CuSO4(s)Copper(II) sulfates-771.36

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Standard Enthalpy of Formation

The standard enthalpy of formation (ΔHf°) is the heat change that occurs when one mole of a compound is formed from its constituent elements in their standard states (298 K, 1 atm). By definition, the ΔHf° of any element in its standard state is zero.

This database includes over 180 compounds — from common substances like water and carbon dioxide to refrigerants like R-134a and industrial chemicals. Values are given in kJ/mol (convertible to kcal/mol). Use these values with Hess's Law to calculate reaction enthalpies: ΔH°reaction = Σ ΔHf°(products) − Σ ΔHf°(reactants).

FAQ: Using Formation Enthalpies
How do I calculate reaction enthalpy from formation values?

ΔH°rxn = Σ n·ΔHf°(products) − Σ m·ΔHf°(reactants), where n and m are stoichiometric coefficients.

What does a negative ΔHf° mean?

A negative value means the compound is more stable than its elements — energy is released during formation. Positive values mean energy must be supplied.

Why are elements listed with ΔHf° = 0?

By convention, the enthalpy of formation of any element in its standard reference state is defined as zero.

Example: Combustion of Methane

Reaction: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(l)

ΔHf°(CH₄) = −74.81, ΔHf°(CO₂) = −393.51, ΔHf°(H₂O,l) = −285.83

ΔH°rxn = [−393.51 + 2(−285.83)] − [−74.81 + 0] = −890.36 kJ/mol