## Example 9.2

$\Delta S = \frac{q_{rev}}{T}$

Angela 1K
Posts: 80
Joined: Fri Sep 29, 2017 7:05 am

### Example 9.2

The question asks: A sample of nitrogen gas of volume 20.0 L at 5.00 kPa is heated from 20. C to 400. C at constant volume. What is the change in the entropy of the nitrogen? The molar heat capacity of nitrogen at constant volume, CV, m is 20.91 J/Kmol.

The textbook solves this question by using $\Delta S=Cln(T2/T1)$ and $C=nC(V,m)$.

I don't understand why they use $C=nC(V,m)$.

Thanks.

snehabhargava
Posts: 52
Joined: Thu Jul 13, 2017 3:00 am

### Re: Example 9.2

It uses Cv,m because there is a constant volume so they can use that heat capacity.

Ozhen Atoyan 1F
Posts: 50
Joined: Thu Jul 27, 2017 3:01 am
Been upvoted: 1 time

### Re: Example 9.2

Since there is a Cv,m does the m stand for constant MOLAR heat capacity?

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