CHEM 204 Lecture Notes - Joule
15 Jul 2013
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Recall: an exact number of joules per less and more likely outcomes. Example chemical reaction: o2(g) + 2h2(g) 2h2o(g), Total number of particles decreased, so there is a decrease in entropy. A: this negative entropy is only the entropy of the system. Consider the fact that the fh of water is -286 kj/mol. The reaction above made 2 moles of water, or -572 kj. The overall entropy including the surroundings was +1590kj for this reaction so it is very likely to happen. This total entropy above is gibb"s free energy. Note: in step 2, we want to add the entropy of the surroundings so we put a negative sign to make the entropy positive. Gibb"s free energy is the mirror opposite of total entropy. Any reaction is trying to increase its total entropy, and thus equivalently every reaction is trying to decrease the gibbs. Rate of reaction is proportional to the slope.
