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Positional/Residual Entropy

Posted: Mon Jan 23, 2017 10:27 am
by Nicole Gamboa 2M
Hi All,
I was going back through what we learned in the course reader about entropy, and I found myself really confused about when you need to calculate positional/residual entropy and what the difference is between the calculations of positional/residual entropy and when you calculate entropy regularly.
Thanks!

Re: Positional/Residual Entropy

Posted: Mon Jan 23, 2017 10:37 am
by Kevin Tam 1J
To my understanding, positional/residual entropy is calculated as the absolute entropy (the equation, I think, was derived through molecular/statistical analysis). The equation for absolute entropy is S=Kb*lnW.

On the other hand, I think that the "regular entropy" that you are talking about is just delta S, or the change in entropy. Delta S can be determined under a change in temperature, a change in volume, a change in pressure, etc.