## Question on 7th edition 4G. 5

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

Michael Novelo 4G
Posts: 64
Joined: Fri Sep 28, 2018 12:28 am

### Question on 7th edition 4G. 5

Hi I was wondering if anyone can assist me on this question I have provided a photo of it. I was wondering why the cis has 12 orientations and why the trans only has 3. I can see why the cis can have 12 orientations but the trans only having 3 orientations is confusing to me. I thought Trans would have 4 orientations since the red circles are on the y axis and there are 2 possible orientations for each red circle on the y axis. If anyone can help explain that'd be great thank you.
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David Effio 1H
Posts: 38
Joined: Wed Feb 14, 2018 3:01 am

### Re: Question on 7th edition 4G. 5

So the Trans would have 3 orientations because it can either be on the y-axis in the configuration shown on the image or across from each other on the "x-plane". That is, a molecule on the left that sticks out and the one on the right inside the page, or the molecule on the right that sticks out and the one on the left that goes into the page.

The fourth one you may be thinking about would be the exact same one as the first one shown in the screenshot. But with that logic, there would technically be six orientations. This wouldn't really make sense, since the two molecules are identical, so there can only be those 3 orientations.

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