From my experience so far with chemistry, it seems like every reaction that happens is to attain stability. So shouldn't a lower entropy be good? Since less disorder means more stability. But by Gibbs Helmholtz equation, a negative entropy change value favors a positive $\Delta G$.... But shouldn't a reaction which leads to stability be spontaneous?

  • $\begingroup$ Second Law of Thermodynamics: the entropy of the universe always increases. $\endgroup$
    – bon
    Jul 16 '17 at 17:31
  • $\begingroup$ Why? Any proof. I don't mean to disrespect any laws... But im curious. I have a hard time just accepting facts without knowing why it is so $\endgroup$ Jul 16 '17 at 17:35
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    $\begingroup$ Less disorder doesn't mean more stability. $\endgroup$
    – orthocresol
    Jul 16 '17 at 17:41
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    $\begingroup$ @ULTIMATEGAMER07 You are asking for a full introductory lecture on thermodynamics. That's not quite what SE is about, I think. Pick up your chemistry textbook, and come back when you have an actual question. $\endgroup$
    – Karl
    Jul 16 '17 at 18:09
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    $\begingroup$ But if you accept a correspondence between entropy and disorder, then this might help: say we have particles zooming around in a box with total energy E. States that look orderly are few and far between; all other states look disorderly. So the disorderly states are far more probable, especially in the thermodynamic limit of infinite particles. Orderly states thus, on average, evolve toward disorderly states, and entropy increases. $\endgroup$ Jul 16 '17 at 18:28

In chemistry it has often been explained that entropy increase had something to do with increasing disorder. The word disorder stems from Helmholtz (1882). But this is outdated, it was only a first attempt at theoretical interpretation.

Entropy = Spreading of energy or of particles of molecular (or sub-molecular) scale against constraints on their free motion. These constraints may be outer (volume) or inner (aggregative) constraints. This spreading leads to quantum mechanical stabilization effects (which may be explained with the “particle in a box”).[1] — This is the reason why entropy increase leads to more stability.

  • $\begingroup$ K thank you very much.... This makes a lot more sense $\endgroup$ Jul 17 '17 at 10:49

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