## 9.23 Determining what has higher entropy state

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

Emily Mei 1B
Posts: 50
Joined: Fri Sep 29, 2017 7:04 am

### 9.23 Determining what has higher entropy state

Which would you expect to have a higher molar entropy at T = 0, single crystals of BF3 or of COF2? Why?
I don't really understand the explanation at the back of the book for this one.

Mitch Mologne 1A
Posts: 74
Joined: Fri Sep 29, 2017 7:04 am

### Re: 9.23 Determining what has higher entropy state

Because there are only F atoms around the B, there is no variability in how the molecule is structured. However, with COF2, the Oxygen atom can be in one of three places, which causes a higher molar entropy.

Riya Pathare 2E
Posts: 74
Joined: Sat Jul 22, 2017 3:01 am
Been upvoted: 1 time

### Re: 9.23 Determining what has higher entropy state

Generally when the molecule tends to be more complex like the COF2 molecule it will have a higher entropy because of the different micro states there are.

Katie Lam 1B
Posts: 52
Joined: Fri Sep 29, 2017 7:06 am

### Re: 9.23 Determining what has higher entropy state

Because COF2 has more microstates, its degeneracy is higher. The different atoms in COF2 can take more positions than the identical atoms in BF3 so it is at a higher entropy state.

Cassidy 1G
Posts: 54
Joined: Fri Sep 29, 2017 7:07 am

### Re: 9.23 Determining what has higher entropy state

I have a follow up question to this... are we saying the three F atoms in BF3 can only be in one set position/they are not interchangeable? It seems like they would still be able to move into different positions.

Return to “Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy”

### Who is online

Users browsing this forum: No registered users and 0 guests