Burdge/Overby, Chemistry: Atoms First, 2e Ch14

580 CHAPTE R 14? Entropy and Free Energy Figure 14.4?? Factors That Influence the Entropy of a System E4 E9 E8 Volume Change Quantum mechanical analysis shows that the spacing between translational energy levels is inversely proportional to the volume of the container. Thus, when the volume is increased, more energy levels become available within which the system’s energy can be dispersed. E7 E3 E6 E E2 E5 E E4 E3 E1 E2 E1 E4 E3 E E4 E3 E2 E1 E Temperature Change At higher temperatures, molecules have greater kinetic energy—making more energy levels accessible. This increases the number of energy levels within which the system’s energy can be dispersed, causing entropy to increase. E2 E1 E4 Molecular Complexity Unlike atoms, which exhibit only translational motion, molecules can also exhibit rotational and vibrational motions. The greater a molecule’s complexity, the greater the number of possible ways it can rotate and vibrate. The ozone molecule (O3), for example, is more complex than the fluorine molecule (F2) and exhibits more different kinds of vibrations and rotations. (See Figure 14.3.) This results in more energy levels within which the system’s energy can be dispersed. The number and spacing of additional energy levels have been simplified to keep the illustration clear. E4 F2 E3 E O3 E3 E E2 E2 E1 E1 580 bur11184_ch14_570-603.indd 580 9/10/13 12:01 PM

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