Entropy, S, is the thermodynamic quantity that is a measure of how spread out or dispersed the energy of a system is among the different possible ways that system can contain energy. It is a quantity that is generally usSed describe the course of a proess, that is, whether it is a spontaneous procese and has a probability of occuring in a definite direction, or a non-spontaneoue process and will not proceed in the defined direction, but in the reveree direction. Most processes are accompanied by entropy change, The folliowing are processes that lead to an increase in entropy of the system Process Order -> Disorder Melting Solid Liquid Vaporization. Liquid Vapor Dissolving Solute Solution Heating System at T1 System at T2 (T2 > T1) Entropy change examples: 1. Gas in balloon spreads out into room and deflates but never a balioon spontaneously filled with air. The molecules of gas at a high pressure always spread to lower pressure regions. 2. Hot coffee in a room gets cooler and the heat spreads out into the room, but never a cold cup of coffee being spontaneously warmed up. PHeats always goes from high temperature into cooler regions. The spreading out of more concentrated moiecules and the spreading out of more concentrated energy are changes from more order to more random. Exercise: FACT OR BLUFF! Directions: Write Fact on the blank if the condition illustrates entropy and write Bluff if does not illustrates entropy. 1. Oxidation of nitrogen 2. Sublimation of mothbalis boc 3. Reduction of silicon 4. Lighting of candies 5. Flow of water up hill 6. Digestion of food 7. Boiling water for tea 8. Flow of heat from a cold body to a hot body 9. Diffusion of LPG 10. Making popcorn