| Substance | Entropy/ J K–1 mol–1 |
| Fe(s) | 27.2 |
| H2O(s) | 41 |
| H2O(l) | 70 |
| H2O(g) | 189 |
| O2(g) | 205 |
The entropy of a substance is higher if more energy levels are available because this increases the number of ways in which the energy can be stored.
The number of energy levels available depends on the temperature .
The graph shows that the entropy of gases, liquids, and solids increases as the temperature is increased due to addition of heat (q).
Addition of heat makes more energy levels available because the particles move faster (have higher kinetic energy) at higher temperatures. Note however that the effect is less at higher temperatures.
Addition of heat makes more energy levels available because the particles move faster (have higher kinetic energy) at higher temperatures. Note however that the effect is less at higher temperatures.
The number of energy levels available depends on the phase of the substance.
The graph shows that
S(gas) > S(liquid) > S(solid)
The graph shows that entropy increases sharply at the melting temperature and at the boiling temperature due to the change in phase.
When considering the different phases of the same substance, there are more energy levels available for a gas than for liquid than for a solid. This is due to the difference in extent of random motion as shown in the videos.
VisChem molecular animations courtesy of Dr Roy Tasker, University of Western Sydney. 1995.
S(gas) > S(liquid) > S(solid)
The graph shows that entropy increases sharply at the melting temperature and at the boiling temperature due to the change in phase.
When considering the different phases of the same substance, there are more energy levels available for a gas than for liquid than for a solid. This is due to the difference in extent of random motion as shown in the videos.
VisChem molecular animations courtesy of Dr Roy Tasker, University of Western Sydney. 1995.
| molecular animation of O2 gas |
| molecular animation of liquid O2 |