## help with example 9.5

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

Miya Eberlein 1J
Posts: 29
Joined: Fri Sep 25, 2015 3:00 am

### help with example 9.5

Where did the Cv,m value of 12.47 J/K*mol come from in Step 2 of example 9.5? Is that something we can look up or was it calculated somewhere..?

Chem_Mod
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### Re: help with example 9.5

It looks like that Cv value is incorrect, because it is for oxygen gas, which is linear, diatomic, so the Cv should be (5/2)*R=20.785 J/(mol*K), rather than the (5/2)*R value that they used.