## Change in S with changes in P, V, and T

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

Justin Lau 1D
Posts: 51
Joined: Sat Jul 22, 2017 3:00 am

### Change in S with changes in P, V, and T

What specific heat capacity is to be used for an ideal gas when there are changes in P, V, and T as pressure and volume are both not constant? Is it even possible for all three to be changed together?

Jingyi Li 2C
Posts: 56
Joined: Fri Sep 29, 2017 7:06 am

### Re: Change in S with changes in P, V, and T

It is not possible for all three to change simultaneously. When T changes, you use the formula with the heat capacity. The problem would tell you if the reaction is under constant P or V, then you would know which heat capacity to use.

Austin Ho 1E
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Joined: Fri Sep 29, 2017 7:04 am
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### Re: Change in S with changes in P, V, and T

I'm in agreement with the statement above - we're probably not going to be asked for all three to change because that would be impossible to calculate with what we know about heat capacities for ideal gases.

Josh Moy 1H
Posts: 58
Joined: Thu Jul 13, 2017 3:00 am

### Re: Change in S with changes in P, V, and T

You wont be asked a problem with all three of those being unknown because its not possible to calculate one without the other 2