## Residual Entropy

Boltzmann Equation for Entropy: $S = k_{B} \ln W$

Riya Sood 4G
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### Residual Entropy

How can we define residual entropy? And what does it tell us?

DarrenKim_1H
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### Re: Residual Entropy

residual entropy is the remaining entropy left in molecules at 0 K

805097738
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### Re: Residual Entropy

DarrenKim_3G wrote:residual entropy is the remaining entropy left in molecules at 0 K

what does that mean? and when will we use this?

Junwei Sun 4I
Posts: 125
Joined: Wed Oct 02, 2019 12:16 am

### Re: Residual Entropy

Residual entropy is essentially the entropy due to positions. A perfectly ordered crystal has an entropy of zero at 0K because it has no thermal entropy neither positional entropy.

Diana_Diep2I
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### Re: Residual Entropy

It is the only entropy that is left after you take out all types of entropy like thermal entropy. When you reduce the temperature and try to get to 0 Kelvin, the molecules would not be in motion. The only entropy that would be left is the positional entropy. One molecule could be in multiple orientations and that is the residual entropy. If it is a perfect crystal and is only in one, perfectly ordered position, the entropy would be 0. But this isn't the case for many molecules so there is some entropy.

Sydney Pell 2E
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### Re: Residual Entropy

Residual entropy (the remaining entropy of molecules when thermal entropy is ignored) is calculated using the equation S= kB lnW.

Tauhid Islam- 1H
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Joined: Fri Aug 02, 2019 12:15 am

### Re: Residual Entropy

Residual entropy is the entropy that remains after molecules stop moving at 0 degrees kelvin. The entropy lies within the orientation of the atoms of the molecule.

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