ChemWhiz ReferenceThermodynamics
Standard Thermodynamic Properties (ΔH°f, ΔG°f, S°)
Standard enthalpy of formation (ΔH°f), standard Gibbs free energy of formation (ΔG°f), and absolute standard entropy (S°) for a curated general-chemistry set of 157 substances at 298.15 K, grouped into ChemWhiz teaching categories (elements, oxides, acids and bases, salts, aqueous ions, organic and other molecular compounds). Use these values with Hess's law (ΔH°rxn = Σ n·ΔH°f products − Σ n·ΔH°f reactants) and with ΔG°rxn = ΔH°rxn − T·ΔS°rxn for spontaneity. Pure elements in their standard reference state have ΔH°f = ΔG°f = 0 by definition.
01Use this when
Hess's-law reaction enthalpy (ΔH°rxn = Σ ΔH°f products − Σ ΔH°f reactants) and ΔG° / S° for spontaneity.
02Conditions
298.15 K (25 °C), 1 bar; aqueous ions at 1 M; an element in its standard state is 0.
03Watch out
Multiply each ΔH°f by its coefficient; do not look up a pure element in its standard state (it is 0).
Standard ΔH°f, ΔG°f, and S° at 298.15 K
Use with Hess's law for reaction enthalpies and with ΔG° = ΔH° − TΔS° for spontaneity.
157 of 157
| Elements (reference states) | Al | s | 0 | 0 | 28.3 |
| Elements (reference states) | Br2 | l | 0 | 0 | 152.23 |
| Elements (reference states) | C | s (graphite) | 0 | 0 | 5.74 |
| Elements (reference states) | C | s (diamond) | 1.89 | 2.9 | 2.38 |
| Elements (reference states) | Ca | s | 0 | 0 | 41.6 |
| Elements (reference states) | Cl2 | g | 0 | 0 | 223.1 |
| Elements (reference states) | Cr | s | 0 | 0 | 23.77 |
| Elements (reference states) | Cu | s | 0 | 0 | 33.15 |
| Elements (reference states) | F2 | g | 0 | 0 | 202.8 |
| Elements (reference states) | Fe | s | 0 | 0 | 27.3 |
| Elements (reference states) | H2 | g | 0 | 0 | 130.7 |
| Elements (reference states) | Hg | l | 0 | 0 | 75.9 |
| Elements (reference states) | I2 | s | 0 | 0 | 116.14 |
| Elements (reference states) | K | s | 0 | 0 | 64.7 |
| Elements (reference states) | Li | s | 0 | 0 | 29.1 |
| Elements (reference states) | Mn | s | 0 | 0 | 32 |
| Elements (reference states) | N2 | g | 0 | 0 | 191.6 |
| Elements (reference states) | Na | s | 0 | 0 | 51.3 |
| Elements (reference states) | O2 | g | 0 | 0 | 205.2 |
| Elements (reference states) | O3 | g | 142.7 | 163.2 | 238.9 |
| Elements (reference states) | P4 | s | 0 | 0 | 164.4 |
| Elements (reference states) | S8 | s (rhombic) | 0 | 0 | 256.8 |
| Elements (reference states) | Si | s | 0 | 0 | 18.8 |
| Elements (reference states) | Sn | s | 0 | 0 | 51.2 |
| Elements (reference states) | Ag | s | 0 | 0 | 42.55 |
| Elements (reference states) | Pb | s | 0 | 0 | 64.81 |
| Elements (reference states) | Zn | s | 0 | 0 | 41.6 |
| Elements (reference states) | S | g | 278.81 | 238.25 | 167.82 |
| Common oxides | CO | g | -110.52 | -137.15 | 197.7 |
| Common oxides | CO2 | g | -393.51 | -394.36 | 213.8 |
| Common oxides | H2O | l | -285.83 | -237.1 | 70 |
| Common oxides | H2O | g | -241.82 | -228.59 | 188.8 |
| Common oxides | H2O2 | l | -187.78 | -120.35 | 109.6 |
| Common oxides | NO | g | 90.25 | 87.6 | 210.8 |
| Common oxides | NO2 | g | 33.2 | 51.3 | 240.1 |
| Common oxides | N2O | g | 81.6 | 103.7 | 220 |
| Common oxides | N2O4 | g | 11.1 | 99.8 | 304.4 |
| Common oxides | SO2 | g | -296.83 | -300.1 | 248.2 |
| Common oxides | SO3 | g | -395.72 | -371.06 | 256.76 |
| Common oxides | Al2O3 | s | -1676 | -1582 | 50.92 |
| Common oxides | Fe2O3 | s | -824.2 | -742.2 | 87.4 |
| Common oxides | Fe3O4 | s | -1118.4 | -1015.4 | 146.4 |
| Common oxides | FeO | s | -272 | -255.2 | 60.75 |
| Common oxides | CuO | s | -157.3 | -129.7 | 42.63 |
| Common oxides | Cu2O | s | -168.6 | -146 | 93.14 |
| Common oxides | ZnO | s | -350.5 | -320.5 | 43.7 |
| Common oxides | CaO | s | -634.9 | -603.3 | 38.1 |
| Common oxides | MgO | s | -601.7 | -569.4 | 26.9 |
| Common oxides | SiO2 | s | -910.7 | -856.3 | 41.5 |
| Common oxides | P4O10 | s | -2984 | -2697 | 228.86 |
| Common oxides | MnO2 | s | -520.03 | -465.1 | 53.05 |
| Common oxides | Mn3O4 | s | -1378.83 | -1283.23 | 155.64 |
| Common oxides | PbO | s (red) | -218.99 | -188.93 | 66.5 |
| Common oxides | PbO2 | s | -277.4 | -217.3 | 68.6 |
| Common oxides | SnO2 | s | -577.6 | -515.8 | 49 |
| Common oxides | TiO2 | s | -944 | -888.8 | 50.6 |
| Common oxides | Cr2O3 | s | -1139.7 | -1058.1 | 81.2 |
| Common oxides | Ag2O | s | -31.05 | -11.2 | 121.3 |
| Common oxides | HgO | s (red) | -90.83 | -58.5 | 70.29 |
| Common oxides | HgO | s (yellow) | -90.46 | -58.43 | 71.13 |
| Acids and bases | HF | g | -273.3 | -275.4 | 173.8 |
| Acids and bases | HCl | g | -92.307 | -95.299 | 186.9 |
| Acids and bases | HBr | g | -36.3 | -53.43 | 198.7 |
| Acids and bases | HI | g | 26.48 | 1.7 | 206.59 |
| Acids and bases | H2S | g | -20.6 | -33.4 | 205.8 |
| Acids and bases | HNO3 | l | -174.1 | -80.7 | 155.6 |
| Acids and bases | HNO3 | aq | -207.4 | -110.5 | 146 |
| Acids and bases | H2SO4 | l | -813.989 | -690 | 156.9 |
| Acids and bases | H3PO4 | s | -1279 | -1119.1 | 110.5 |
| Acids and bases | H3PO4 | l | -1266.9 | -1124.3 | 110.5 |
| Acids and bases | NH3 | g | -45.9 | -16.5 | 192.8 |
| Acids and bases | NaOH | s | -425.6 | -379.5 | 64.5 |
| Acids and bases | KOH | s | -424.8 | -379.1 | 78.9 |
| Acids and bases | Ca(OH)2 | s | -985.2 | -897.5 | 83.4 |
| Acids and bases | Mg(OH)2 | s | -924.5 | -833.6 | 63.2 |
| Acids and bases | Li(OH) | s | -487.5 | -441.5 | 42.8 |
| Salts and ionic solids | NaCl | s | -411.2 | -384.1 | 72.1 |
| Salts and ionic solids | KCl | s | -436.5 | -408.5 | 82.6 |
| Salts and ionic solids | KF | s | -576.27 | -537.75 | 66.57 |
| Salts and ionic solids | LiF | s | -616 | -587.5 | 35.7 |
| Salts and ionic solids | CaCl2 | s | -795.8 | -748.1 | 104.6 |
| Salts and ionic solids | CaCO3 | s (calcite) | -1220 | -1081.4 | 110 |
| Salts and ionic solids | Na2CO3 | s | -1130.7 | -1044.5 | 135 |
| Salts and ionic solids | Li2CO3 | s | -1216.04 | -1132.19 | 90.17 |
| Salts and ionic solids | KNO3 | s | -494.6 | -394.9 | 133.1 |
| Salts and ionic solids | NH4Cl | s | -314.43 | -202.87 | 94.6 |
| Salts and ionic solids | NH4NO3 | s | -365.56 | -183.87 | 151.08 |
| Salts and ionic solids | AgCl | s | -127 | -109.8 | 96.3 |
| Salts and ionic solids | AgNO3 | s | -124.4 | -33.5 | 140.9 |
| Salts and ionic solids | PbCl2 | s | -359.4 | -314.1 | 136 |
| Salts and ionic solids | ZnCl2 | s | -415.1 | -369.43 | 111.5 |
| Salts and ionic solids | FeCl3 | s | -399.49 | -334 | 142.3 |
| Salts and ionic solids | CaSO4 | s | -1434.5 | -1322 | 106.5 |
| Salts and ionic solids | CaSO4·2H2O | s | -2022.63 | -1797.45 | 194.14 |
| Salts and ionic solids | BaSO4 | s | -1473.2 | -1362.3 | 132.2 |
| Salts and ionic solids | CuSO4 | s | -771.36 | -662.2 | 109.2 |
| Salts and ionic solids | ZnSO4 | s | -982.8 | -871.5 | 110.5 |
| Salts and ionic solids | PbS | s | -100.4 | -98.7 | 91.2 |
| Salts and ionic solids | CuS | s | -53.1 | -53.6 | 66.5 |
| Salts and ionic solids | ZnS | s | -206 | -201.3 | 57.7 |
| Salts and ionic solids | FeS | s | -100 | -100.4 | 60.29 |
| Salts and ionic solids | Ag2S | s | -32.6 | -40.7 | 144 |
| Aqueous ions | H+ | aq | 0 | 0 | 0 |
| Aqueous ions | Na+ | aq | -240.1 | -261.9 | 59 |
| Aqueous ions | K+ | aq | -252.4 | -283.3 | 102.5 |
| Aqueous ions | Li+ | aq | -278.5 | -293.3 | 13.4 |
| Aqueous ions | NH4+ | aq | -132.5 | -79.31 | 113.4 |
| Aqueous ions | Ca2+ | aq | -542.96 | -553.04 | -55.2 |
| Aqueous ions | Mg2+ | aq | -466.9 | -454.8 | -138.1 |
| Aqueous ions | Ba2+ | aq | -537.6 | -560.8 | 9.6 |
| Aqueous ions | Al3+ | aq | -531 | -485 | -321.7 |
| Aqueous ions | Zn2+ | aq | -153.9 | -147.1 | -112.1 |
| Aqueous ions | Fe2+ | aq | -89.1 | -78.9 | -137.7 |
| Aqueous ions | Fe3+ | aq | -48.5 | -4.7 | -315.9 |
| Aqueous ions | Cu2+ | aq | 64.77 | 65.49 | -99.6 |
| Aqueous ions | Ag+ | aq | 105.6 | 77.11 | 72.68 |
| Aqueous ions | Pb2+ | aq | -1.7 | -24.43 | 10.5 |
| Aqueous ions | Mn2+ | aq | -220.8 | -228.1 | -73.6 |
| Aqueous ions | OH- | aq | -230 | -157.2 | -10.75 |
| Aqueous ions | Cl- | aq | -167.2 | -131.2 | 56.5 |
| Aqueous ions | Br- | aq | -120.9 | -102.82 | 80.71 |
| Aqueous ions | I- | aq | -55.19 | -51.57 | 11.13 |
| Aqueous ions | F- | aq | -332.6 | -278.8 | -13.8 |
| Aqueous ions | NO3- | aq | -205 | -108.7 | 146.4 |
| Aqueous ions | SO42- | aq | -909.3 | -744.5 | 20.1 |
| Aqueous ions | CO32- | aq | -677.1 | -527.8 | -56.9 |
| Aqueous ions | HCO3- | aq | -691.11 | -587.06 | 95 |
| Aqueous ions | PO43- | aq | -1277 | -1019 | -222 |
| Aqueous ions | HSO4- | aq | -885.75 | -752.87 | 126.9 |
| Aqueous ions | MnO4- | aq | -541.4 | -447.2 | 191.2 |
| Aqueous ions | CrO42- | aq | -881.2 | -727.8 | 50.21 |
| Aqueous ions | Cr2O72- | aq | -1490.3 | -1301.1 | 261.9 |
| Aqueous ions | S2- | aq | 41.8 | 83.7 | 22 |
| Organic compounds | CH4 | g | -74.6 | -50.5 | 186.3 |
| Organic compounds | C2H2 | g | 227.4 | 209.2 | 200.9 |
| Organic compounds | C2H4 | g | 52.4 | 68.4 | 219.3 |
| Organic compounds | C2H6 | g | -84 | -32 | 229.2 |
| Organic compounds | C3H8 | g | -103.8 | -23.4 | 270.3 |
| Organic compounds | C6H6 | l | 49.1 | 124.5 | 173.4 |
| Organic compounds | C6H6 | g | 82.927 | 129.66 | 269.2 |
| Organic compounds | CH3OH | l | -239.2 | -166.6 | 126.8 |
| Organic compounds | CH3OH | g | -201 | -162.3 | 239.9 |
| Organic compounds | C2H5OH | l | -277.6 | -174.8 | 160.7 |
| Organic compounds | C2H5OH | g | -234.8 | -167.9 | 281.6 |
| Organic compounds | CH3CO2H | l | -484.3 | -389.9 | 159.8 |
| Organic compounds | HCN | g | 135.5 | 124.7 | 201.8 |
| Organic compounds | CCl4 | l | -128.2 | -62.5 | 214.4 |
| Organic compounds | CHCl3 | l | -134.1 | -73.7 | 201.7 |
| Organic compounds | CH2Cl2 | l | -124.2 | -63.2 | 177.8 |
| Organic compounds | CH3Cl | g | -81.9 | -60.2 | 234.6 |
| Organic compounds | CS2 | l | 89.7 | 65.27 | 151.34 |
| Other molecular compounds | PH3 | g | 5.4 | 13.5 | 210.2 |
| Other molecular compounds | SiH4 | g | 34.3 | 56.9 | 204.6 |
| Other molecular compounds | N2H4 | l | 50.63 | 149.43 | 121.21 |
| Other molecular compounds | SbCl3 | g | -313.8 | -301.2 | 337.8 |
| Other molecular compounds | SbCl5 | g | -394.34 | -334.29 | 401.94 |
| Other molecular compounds | ICl | g | 17.78 | -5.44 | 247.44 |
Important Notes
- All values at 298.15 K (25 °C) and 1 bar; aqueous ions referenced to 1 mol/L with S°(H+, aq) ≡ 0.
- Pure elements in their standard reference state (graphite for C; H2, N2, O2 as gases; etc.) have ΔH°f = ΔG°f = 0 by definition.
- Use Hess's law: ΔH°rxn = Σ n·ΔH°f(products) − Σ n·ΔH°f(reactants), where n is the stoichiometric coefficient.
- For ΔG°rxn use ΔG°rxn = ΔH°rxn − T·ΔS°rxn (T in K, ΔS° in J/(mol·K), convert to kJ before combining).
- A few substances list more than one form in the Phase column (e.g. s (graphite) vs s (diamond) for carbon); pick the form your problem specifies.
- This is a curated general-chemistry teaching set (157 substances) organized by category, at authoritative standard-reference-table values; every species a ChemWhiz problem tells you to look up here appears with the cited value.
- Aqueous-ion entropies are NOT absolute, they're referenced to S°(H+, aq) ≡ 0. Negative S° values for ions are real (relative to that convention).
Verification references: OpenStax Chemistry 2e, Appendix G; NBS Technical Note 270-4; TN 270-6; TN 270-8; NIST Chemistry WebBook.