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 04-26-2012, 03:04 PM #1 Always confused   Join Date: Aug 2011 Posts: 242 2nd law of thermodynamics SDN Members don't see this ad. (About Ads) 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).
 04-26-2012, 03:50 PM #2 Member   Status: Pre-Dental Join Date: Feb 2012 Posts: 59 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
 04-26-2012, 09:03 PM #3 Always confused   Join Date: Aug 2011 Posts: 242 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.
 04-26-2012, 09:56 PM #4 Member     Status: Pre-Dental Join Date: Mar 2011 Posts: 52 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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