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Laws of Thermodynamics

Discussion in 'DAT Discussions' started by CrentistTheDentist, Aug 7, 2015.

  1. CrentistTheDentist

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    In Destroyer, there was a question that states:

    Which statements are representative of the second law of thermodynamics?

    a) Systems tend to move towards greater disorder (entropy)
    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 are true

    Now I put choice A because that's what the second law states but the solutions say that the answer choice E is correct. I'm confused because energy transfers and heat loss described for choices B and D are indicative of the first law of thermodynamics, represented by the equation E (delta E) = q + w.

    Any clarification is appreciated, I want to know all possible ways the second and first laws are stated. Thank you guys
     
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  3. orgoman22

    orgoman22 DAT DESTROYER
    Lifetime Donor Sponsor Exhibitor Classifieds Approved 10+ Year Member

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    The second law of thermodynamics is a continuation of the first law. The first law states that energy can neither be created or destroyed. It must be transferred from somewhere. The second law of thermodynamics basically states that heat only flows in one direction, from higher concentration to lower concentration. In order for it to flow in reverse energy input is needed. To better illustrate this concept, the term entropy(disorder) was created.
    It is observed that over time, systems (spontaneously) will move towards more disorder. Since, some work for that will be required, it will amount to some energy loss.

    For example lets take a spontaneous decomposition reaction: H2CO3 will decompose to CO2 and H2O
    It moves towards disorder, by creating more particles, as well as releases some energy, because bond was broken

    Hope this helps.
     

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