### Entropy as three steps

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**Wed Feb 05, 2020 5:34 pm**For 4.17, it asks us "Calculate the standard entropy of vaporization of water at 85 degrees C, given that its standard entropy of vaporization at 100 degrees C is 109.0 J/Kmol and the molar heat capacities at constant pressure of liquid water and water vapor are 75.3 J/Kmol and 33.6 J/Kmol, respectively, in this range."

In the solutions, entropy is broken up into three steps: heating, vaporizing, and then cooling. Can someone explain why you have to cool the product back down at 85C if you are vaporizing it?

In the solutions, entropy is broken up into three steps: heating, vaporizing, and then cooling. Can someone explain why you have to cool the product back down at 85C if you are vaporizing it?