## 9.73 and delta S tot

$\Delta S = \frac{q_{rev}}{T}$

ClaireHW
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Joined: Fri Sep 29, 2017 7:07 am
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### 9.73 and delta S tot

How does delta S tot determine spontaneity?
I am confused to the difference between delta S and delta S tot.

(Claire Woolson Dis 1K)

Cooper1C
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

### Re: 9.73 and delta S tot

The third law of thermodynamics says that the total entropy is always increasing, so delta S total must be positive. The standard enthalpy for a reaction can be positive or negative depending on the reaction. For example, building polymers from monomers has a negative delta S (the complexity is increasing), but breaking down polymers to form monomers has a positive delta S (the complexity is decreasing).