## chen discussion [ENDORSED]

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

connie 2C
Posts: 106
Joined: Thu Jul 11, 2019 12:17 am

### chen discussion

for #1, we used the equation delta s= nRln(V2/V1). what is n equal to in the problem? is it equal to 1 because we are calculating molar entropy?

Michelle Song 1I
Posts: 102
Joined: Thu Jul 11, 2019 12:17 am

### Re: chen discussion

Do you mind posting the entire question?

connie 2C
Posts: 106
Joined: Thu Jul 11, 2019 12:17 am

### Re: chen discussion

the question is "calculate the change in molar entropy of carbon dioxide that is allowed to expand isothermally to 10 times its initial volume (treat carbon dioxide as an ideal gas, Cv,m=3/2R)"

Chem_Mod
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### Re: chen discussion  [ENDORSED]

Yes, molar entropy means entropy for 1 mole of substance. So number of mole equals to one in this question.

Diana_Diep2I
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Joined: Sat Aug 17, 2019 12:17 am

### Re: chen discussion

When do we use C and when do we use R?

ELu 1J
Posts: 51
Joined: Thu Jul 25, 2019 12:16 am

### Re: chen discussion

Diana_Diep2I wrote:When do we use C and when do we use R?

C = 3/2R at constant volume and C = 5/2R at constant pressure.

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