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Old 04-26-2012, 03:04 PM   #1
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Default 2nd law of thermodynamics


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I had a question asking which statements applied to the 2nd law of thermodynamics:

a) systems tend to move towards greater disorder
b) energy transfers are always accompanied by some amount of loss
c) energy is required for highly organized systems
d) for most systems, heat represents lost energy
e) all of the above

how come the answer was E? The second law I thought only discusses that spontaneous reactions increase in entropy of the universe and tend to do that for the surroundings and system as well (but not always).
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Old 04-26-2012, 03:50 PM   #2
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I was a tad bit confused with this question too. I took it as "different ways" to describe the second law. Generally speaking, I think of the second law as anything that has to do with increasing entropy if the reaction is spontaneous, therefore A, B, and D are "somewhat" talking about it... Not sure if that answered your question but that's just how I thought about that question which led me to the "correct" answer when I first did that question in the destroyer
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Old 04-26-2012, 09:03 PM   #3
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yeah, A for sure sounds like the 2nd law. How does the increasing entropy and all that relate to energy/heat? I think I'm missing a huge gap in my thermodynamics knowledge lol.
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Old 04-26-2012, 09:56 PM   #4
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The whole idea of entropy has everything to do with heat/energy actually. By increasing the heat you cause more disorder which increases entropy and by decreasing heat you cause less disorder and less entropy. When it says that energy transfer is accompanied by some amount of loss, that means that if you change the entropy in a particular environment (the system) the entropy of the surroundings are affected as well. For instance ice floating in a glass of water, the ice gets warmer and melts so the entropy of the ice is increasing and the water gets colder from the melted ice so the water's entropy is decreasing. So energy is being transferred all the time in order for the overall entropy of the universe to increase.
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