Unformatted text preview: e Boltzmann constant. Therefore, from a
microscopic point of view, the entropy of a system increases whenever the
molecular randomness or uncertainty (i.e., molecular probability) of a system
increases. Thus, entropy is a measure of molecular disorder, and the molecular disorder of an isolated system increases anytime it undergoes a process.
Molecules in the gas phase possess a considerable amount of kinetic energy.
However, we know that no matter how large their kinetic energies are, the gas
molecules will not rotate a paddle wheel inserted into the container and cen54261_ch07.qxd 11/18/03 9:57 AM Page 289 289
CHAPTER 7 produce work. This is because the gas molecules, and the energy they possess,
are disorganized. Probably the number of molecules trying to rotate the wheel
in one direction at any instant is equal to the number of molecules that are trying to rotate it in the opposite direction, causing the wheel to remain motionless. Therefore, we cannot extract any useful work directly from disorganized
energy (Fig. 7–21).
Now consider a r...
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