The Committee on Data for Science and Technology (CODATA) conducted a project to establish internationally agreed values for the thermodynamic properties of key chemical substances. This table presents the final results of the project. Use of these recommended, internally consistent values is encouraged in the analysis of thermodynamic measurements, data reduction, and preparation of other thermodynamic tables.
The table includes the standard enthalpy of formation at 298.15 K, the entropy at 298.15 K, and the quantity H°(298.15 K)–H°(0). A value of 0 in the ∆fH° column for an element indicates the reference state for that element. The standard state pressure is 100,000 Pa (1 bar). See the reference for information on the dependence of gas-phase entropy on the choice of standard state pressure.
Column definitions for the table are as follows.
Column heading | Definition |
Name | Chemical substance name (Online Edition only) |
Mol. form. | Molecular formula; substances are listed in alphabetical order of their chemical formulas when written in the most common form |
Phys. state | Physical state; g = gas; cr = crystalline; aq = aqueous; l = liquid; for some physical states, the crystal system or other information is also given |
ΔfHº(298) | Standard enthalpy of formation at 298.15 K |
Sº(298) | Entropy at 298.15 K |
Hº(298)-Hº(0) | Enthalpy difference between 298.15 K and 0 K |
The table is reprinted with permission of CODATA.
Mol. form. | Synonym | Phys. state | CAS Reg. No. | Mol. wt. | ΔfHº(298)/ kJ mol-1 | Sº(298)/ J mol-1 K-1 | Hº(298)-Hº(0)/ kJ mol-1 | |
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Ag | Silver | cr | 7440-22-4 | 107.868 | 0 | 42.55 ± 0.20 | 5.745 ± 0.020 | |
Ag | Silver | g | 7440-22-4 | 107.868 | 284.9 ± 0.8 | 172.997 ± 0.004 | 6.197 ± 0.001 | |
Ag+ | Silver ion [Ag+] | aq | 14701-21-4 | 107.868 | 105.79 ± 0.08 | 73.45 ± 0.40 | ||
AgCl | Silver(I) chloride | Cerargyrite | cr | 7783-90-6 | 143.321 | -127.01 ± 0.05 | 96.25 ± 0.20 | 12.033 ± 0.020 |
Al | Aluminum | cr | 7429-90-5 | 26.982 | 0 | 28.30 ± 0.10 | 4.540 ± 0.020 | |
Al | Aluminum | g | 7429-90-5 | 26.982 | 330.0 ± 4.0 | 164.554 ± 0.004 | 6.919 ± 0.001 | |
Al+3 | Aluminum ion [Al+3] | aq | 22537-23-1 | 26.982 | -538.4 ± 1.5 | -325 ± 10 | ||
AlF3 | Aluminum fluoride | Aluminum trifluoride | cr | 7784-18-1 | 83.977 | -1510.4 ± 1.3 | 66.5 ± 0.5 | 11.62 ± 0.04 |
Al2O3 | Aluminum oxide (α) | Corundum | cr, corundum | 1344-28-1 | 101.961 | -1675.7 ± 1.3 | 50.92 ± 0.10 | 10.016 ± 0.020 |
Ar | Argon | g | 7440-37-1 | 39.948 | 0 | 154.846 ± 0.003 | 6.197 ± 0.001 | |
B | Boron | cr, rhombic | 7440-42-8 | 10.81 | 0 | 5.90 ± 0.08 | 1.222 ± 0.008 | |
B | Boron | g | 7440-42-8 | 10.81 | 565 ± 5 | 153.436 ± 0.015 | 6.316 ± 0.002 | |
BF3 | Boron trifluoride | Trifluoroborane | g | 7637-07-2 | 67.806 | -1136.0 ± 0.8 | 254.42 ± 0.20 | 11.650 ± 0.020 |
B2O3 | Boron oxide | Boric oxide | cr | 1303-86-2 | 69.620 | -1273.5 ± 1.4 | 53.97 ± 0.30 | 9.301 ± 0.040 |
Be | Beryllium | Glucinium | cr | 7440-41-7 | 9.012 | 0 | 9.50 ± 0.08 | 1.950 ± 0.020 |
Be | Beryllium | Glucinium | g | 7440-41-7 | 9.012 | 324 ± 5 | 136.275 ± 0.003 | 6.197 ± 0.001 |
BeO | Beryllium oxide | Beryllia | cr | 1304-56-9 | 25.011 | -609.4 ± 2.5 | 13.77 ± 0.04 | 2.837 ± 0.008 |
Br- | Bromide ion [Br-] | aq | 24959-67-9 | 79.904 | -121.41 ± 0.15 | 82.55 ± 0.20 | ||
Br | Bromine (atomic) | g | 10097-32-2 | 79.904 | 111.87 ± 0.12 | 175.018 ± 0.004 | 6.197 ± 0.001 |