Melting and boiling: enthalpies and entropies
Enthalpies of fusion and vaporization of common substances and metals at their normal melting and boiling points, with the transition entropies ΔS = ΔH/T. Trouton’s rule and the kinks of Ellingham lines come from this table.
| Helium | vaporization | 4.22 | 0.0829 | 19.6 | — | |
|---|---|---|---|---|---|---|
| Neon | vaporization | 27.07 | 1.71 | 63.2 | — | |
| Nitrogen | vaporization | 77.36 | 5.57 | 72.0 | — | |
| Argon | vaporization | 87.3 | 6.43 | 73.7 | — | |
| Oxygen | vaporization | 90.2 | 6.82 | 75.6 | — | |
| Methane | vaporization | 111.67 | 8.19 | 73.3 | — | |
| Krypton | vaporization | 119.93 | 9.08 | 75.7 | — | |
| Xenon | vaporization | 165.05 | 12.57 | 76.2 | — | |
| Hydrogen sulfide | vaporization | 213.6 | 18.67 | 87.4 | — | |
| Chlorine | vaporization | 239.11 | 20.41 | 85.4 | — | |
| Ammonia | vaporization | 239.82 | 23.33 | 97.3 | yes | |
| Acetone | vaporization | 329.22 | 29.1 | 88.4 | — | |
| Bromine | vaporization | 331.95 | 29.96 | 90.3 | — | |
| Methanol | vaporization | 337.8 | 35.21 | 104.2 | yes | |
| Hexane | vaporization | 341.88 | 28.85 | 84.4 | — | |
| Tetrachloromethane | vaporization | 349.79 | 29.82 | 85.3 | — | |
| Ethanol | vaporization | 351.44 | 38.56 | 109.7 | yes | |
| Benzene | vaporization | 353.24 | 30.72 | 87.0 | — | |
| Water | vaporization | 373.12 | 40.65 | 109.0 | yes | |
| Mercury | vaporization | 629.88 | 59.11 | 93.8 | — | |
| Nitrogen | fusion | 63.15 | 0.71 | 11.2 | — | |
| Argon | fusion | 83.8 | 1.18 | 14.1 | — | |
| Methane | fusion | 90.69 | 0.94 | 10.4 | — | |
| Ethanol | fusion | 159 | 4.931 | 31.0 | — | |
| Mercury | fusion | 234.32 | 2.29 | 9.8 | — | |
| Water (ice) | fusion | 273.15 | 6.01 | 22.0 | yes | |
| Benzene | fusion | 278.68 | 9.87 | 35.4 | — | |
| Sodium | fusion | 370.87 | 2.6 | 7.0 | — | |
| Aluminium | fusion | 933.47 | 10.71 | 11.5 | — | |
| Sodium chloride | fusion | 1073.8 | 28.16 | 26.2 | — | |
| Iron | fusion | 1811 | 13.81 | 7.6 | — | |
| Lithium | fusion | 453.65 | 3 | 6.6 | — | |
| Lithium | vaporization | 1615 | 147.1 | 91.1 | — | |
| Sodium | vaporization | 1156 | 97.42 | 84.3 | — | |
| Magnesium | fusion | 923 | 8.48 | 9.2 | — | |
| Magnesium | vaporization | 1363 | 127.4 | 93.5 | — | |
| Calcium | fusion | 1115 | 8.54 | 7.7 | — | |
| Calcium | vaporization | 1757 | 154.7 | 88.0 | — | |
| Aluminium | vaporization | 2792 | 294 | 105.3 | — | |
| Silicon | fusion | 1687 | 50.21 | 29.8 | — | |
| Silicon | vaporization | 3538 | 359 | 101.5 | — | |
| Titanium | fusion | 1941 | 14.15 | 7.3 | — | |
| Titanium | vaporization | 3560 | 425 | 119.4 | — | |
| Chromium | fusion | 2180 | 21 | 9.6 | — | |
| Chromium | vaporization | 2944 | 339.5 | 115.3 | — | |
| Manganese | fusion | 1519 | 12.91 | 8.5 | — | |
| Manganese | vaporization | 2334 | 221 | 94.7 | — | |
| Iron | vaporization | 3134 | 349.6 | 111.5 | — | |
| Nickel | fusion | 1728 | 17.48 | 10.1 | — | |
| Nickel | vaporization | 3186 | 377.5 | 118.5 | — | |
| Copper | fusion | 1357.77 | 13.26 | 9.8 | — | |
| Copper | vaporization | 2835 | 300.4 | 106.0 | — | |
| Zinc | fusion | 692.68 | 7.068 | 10.2 | — | |
| Zinc | vaporization | 1180 | 115.3 | 97.7 | — | |
| Silver | fusion | 1234.93 | 11.28 | 9.1 | — | |
| Silver | vaporization | 2435 | 254.1 | 104.3 | — | |
| Tin | fusion | 505.08 | 7.173 | 14.2 | — | |
| Tin | vaporization | 2875 | 296.1 | 103.0 | — | |
| Lead | fusion | 600.61 | 4.774 | 8.0 | — | |
| Lead | vaporization | 2022 | 179.5 | 88.8 | — |
Normal melting and boiling points are at 1 atm; enthalpies are at those temperatures. Most non-associated liquids have vaporization entropies near 85 J/(K·mol) (Trouton’s rule); hydrogen-bonded liquids such as water, alcohols and ammonia are clearly higher.