## S=klnW

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

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William Lan 2l
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Joined: Fri Sep 29, 2017 6:07 am

### S=klnW

In general, in what instance will we be required to use this equation?? like in what context?

Lisa Tang 1C
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### Re: S=klnW

You would use this equation if the question asked you to calculate absolute entropy (instead of the change in entropy) of a system.

Yea Eun Lee 1H
Posts: 33
Joined: Fri Sep 29, 2017 6:06 am

### Re: S=klnW

you'd also use this equation if some information is given about W (like any info about number of ways a molecule can exist)

Sammy Thatipelli 1B
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### Re: S=klnW

you use S=klnW when you are trying to find the entropy when dealing with the fact that molecules can be rearranged in various ways. You will use the Boltzman's constant and then multiply that by the degeneracy, which show the multiple states the molecules can occupy/be in. This gives you the total disorder for the various states the molecule can be displayed in.
For these kinds of questions, I recommend that you draw out the different states that can be produced when switching around the placement of the individual atoms (which make up the molecule).

Clarissa Molina 1D
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### Re: S=klnW

Can someone explain what residual entropy is and is it found from just using this equation?

Rishi Khettry 1L
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Joined: Fri Sep 29, 2017 6:05 am

### Re: S=klnW

Residual enthalpy can be calculated when a reaction is taking place at a very low temperature almost close to 0

Cynthia Bui 2H
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Joined: Fri Sep 29, 2017 6:05 am

### Re: S=klnW

This is total entropy, not change in entropy which is what we normally tend to calculate. You would use this when given a number of molecules and the possible orientations they can lay in and such. For example if a solid had 64 molecules and the molecules can like in any 4 directions, W= 4^64

Troy Tavangar 1I
Posts: 50
Joined: Fri Sep 29, 2017 6:04 am

### Re: S=klnW

This is used for finding total entropy.

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