FL 5, C/P, 40

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FL 5, C/P, 40

Post by NS_Tutor_Katelyn » Mon Jul 09, 2018 1:31 pm

A student asked us: "This question asks about the loss of latent heat energy AND entropy. Implying the loss of both latent heat energy and entropy. A loss of entropy is an increase in ORDER. Evaporation (the suggested correct answer) is a decrease in order / increase in entropy; ie. moving from a liquid to gaseous phase. While I was unfamiliar with the loss of latent heat energy, I did choose the answer which accounts for the loss or decrease in entropy, ie. the increase in order, which is Condensation. It seems there is a contradiction in the question which needs to be addressed. Please let me know if I am incorrect in my thinking. Thank you."

The student is correct in their understanding of entropy, but incorrect in their application of it to phase changes. During the process of evaporation the ocean is losing entropy by way of losing high energy particles, while the atmosphere gains entropy by way of gaining those high energy particles. That is why evaporation is the correct answer. Condensation would have the opposite effect, the ocean would be gaining low energy particles, which would be a loss of entropy.

Katelyn Sawyer
Senior Tutor
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