(December 10, 2009 at 3:59 pm)rjh4 Wrote:(December 3, 2009 at 2:54 pm)Purple Rabbit Wrote: Nope, that is not at all what the second law states. Please be sure not to parrot something you do not understand.
What decreases according to the second law is entropy.
Reading all this stuff about thermodynamics brings back memories....
I happened to read this and I also happened to still have my "Introduction to Chemical Engineering Thermodynamics" book by Smith and Van Ness sitting on my shelf. On page 153 it says:
"Thus, the second law provides us with a general principle of great utility: All processes proceed in a direction such that the total entropy change is positive, approaching zero as a limit, as the process approaches reversibility. This conclusion can be stated mathematically by the equation
delta S total is greater than or equal to 0" (I wrote the equation out obviously)
Since delta S = S final - S initial and delta S is always positive or 0, S must always either increase or stay the same in a process. It never decreases for the total system.
So it seems you are incorrect in your last statement quoted above or you misspoke or...
Could be a typo, you're absolutely correct all the same rjh4, entropy can never decrease in a closed or isolated system, only in an open system.
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