Final answer:
Entropy is a measure of disorder or randomness in a system, with high entropy indicating high disorder and low energy. It's a microscopic concept that applies to the distribution of thermal energy and increases according to the second law of thermodynamics.
Step-by-step explanation:
Understanding Entropy
Chemists describe entropy as a measure of the randomness or disorder within a system. However, equating entropy with disorder must be done with care, as this concept applies fundamentally to microscopic systems at the molecular level, which can exchange thermal energy with their surroundings. High entropy suggests a high level of disorder and low energy available for doing work. For example, gases exhibit higher entropy compared to liquids and solids due to the more spread-out nature of their molecules, as indicated in Figure 6.12 and Figure 2.22. The second law of thermodynamics posits that entropy generally increases in systems, especially as energy is lost as heat during energy transfers or transformations. This is observable in phenomena like diffusion or the reaching of chemical equilibrium in reactions. Caution must be taken not to oversimplify the concept of entropy by equating it to disorder in macroscopic systems, which can be misleading and depart from the scientific meaning as noted by thermodynamics.