Calculating W

Boltzmann Equation for Entropy:

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Lindsey Chheng 1E
Posts: 110
Joined: Fri Aug 30, 2019 12:16 am

Calculating W

Postby Lindsey Chheng 1E » Tue Feb 04, 2020 9:32 pm

In the notes about microstates, it says For 1 mol, W = 2^NA, which means that S = kBlnW = kBln2^NA = NAkBln2 = Rln2.
In the last step, why does NAkB = R? What is R?

Caitlyn Tran 2E
Posts: 100
Joined: Fri Aug 09, 2019 12:15 am

Re: Calculating W

Postby Caitlyn Tran 2E » Tue Feb 04, 2020 10:18 pm

This is just saying that multiplying Avogadro's number with the Boltzmann's constant will equal the constant R. If you look on your constants and equations sheet, there is a constant R listed at the top, which is the constant we use in equations like PV = nRT. Hope this helps!

Kimberly Koo 2I
Posts: 99
Joined: Sat Aug 17, 2019 12:17 am

Re: Calculating W

Postby Kimberly Koo 2I » Wed Feb 05, 2020 12:19 am

R is the universal gas constant, which is equal to 8.314 J/mol.K

Eunice Nguyen 4I
Posts: 100
Joined: Sat Aug 17, 2019 12:17 am

Re: Calculating W

Postby Eunice Nguyen 4I » Wed Feb 05, 2020 9:45 am

When you remove ln2 from both sides, it's just multiplying Avogadro's number(NA) with Boltzmann's constant (kB) to equal the gas constant (R). R depends on which units you are using in the problem, but typically is 8.314 J/mol*K.


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