## change in entropy with change in temperature

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

Ekayana Sethi 2K
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### change in entropy with change in temperature

is deltaS=n*R*ln(T2/T1) or deltaS=n*C*ln(T2/T1)? because the book uses both. Also when do we know which one to use when?

Clarisse Wikstrom 1H
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### Re: change in entropy with change in temperature

You use the one with R when you have V1/V2. You use the one with C when you have T1/T2.

Kevin Ru 1D
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Joined: Thu Jul 13, 2017 3:00 am

### Re: change in entropy with change in temperature

Just adding onto the above post. The first equation is looking at when the change in volume is positive; therefore entropy is increasing. The second one occurs under constant pressure and we are looking at the change in temperature. Here, lower temperature means higher entropy. Hope that helps!