### Using dS vs change in S

Posted:

**Sun Feb 04, 2018 3:32 pm**Can anyone give a clear distinction between when you use dS to solve a problem rather that changeS for calculating the general change in entropy?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=131&t=26843

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Posted: **Sun Feb 04, 2018 3:32 pm**

Can anyone give a clear distinction between when you use dS to solve a problem rather that changeS for calculating the general change in entropy?

Posted: **Sun Feb 04, 2018 3:37 pm**

Most likely never. Using dS involves using calculus and integrals, which isn't mainly the whole focus of the class. I see that there's no real reason in order to derive the answer from dS. In fact, most of the time you can relate dS to change in S. After all, dS can be thought of as the change in S.

Posted: **Sun Feb 04, 2018 3:52 pm**

dS is the instantaneous rate of change at a specific point.

is the change in entropy.

So far, we just had to find .

is the change in entropy.

So far, we just had to find .

Posted: **Sun Feb 04, 2018 7:31 pm**

I think dS is mainly used in proofs as a part of integral calculus and deltaS is what we are actually solving for.