## textbook problem 9.25

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

Kayla Danesh 1F
Posts: 38
Joined: Thu Jul 13, 2017 3:00 am

### textbook problem 9.25

9.25 If SO2F2 adopts a positionally disordered arrangement in its crystal form, what might its residual molar entropy be?

I am not sure how to approach this problem. Can someone please explain to me the difference between "positionally disordered arrangement" and "residual entropy" ? thanks

Nancy Dinh 2J
Posts: 59
Joined: Fri Sep 29, 2017 7:07 am

### Re: textbook problem 9.25

Kayla Danesh 1F wrote:9.25 If SO2F2 adopts a positionally disordered arrangement in its crystal form, what might its residual molar entropy be?

I am not sure how to approach this problem. Can someone please explain to me the difference between "positionally disordered arrangement" and "residual entropy" ? thanks

Positionally disordered arrangement just means that the atoms do not all have the same position. This means you would have to determine how many possible micro states there are because there is more than one. Residual entropy is the entropy left over due to the positional arrangement at T = O Kelvin. Only when all of the atoms only have 1 arrangement (and therefore is perfect crystal) will the entropy be 0 at T = 0.

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