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change in entropy with change in temperature

Posted: Sun Feb 04, 2018 10:43 pm
by Ekayana Sethi 2K
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?

Re: change in entropy with change in temperature

Posted: Sun Feb 04, 2018 10:45 pm
by Clarisse Wikstrom 1H
You use the one with R when you have V1/V2. You use the one with C when you have T1/T2.

Re: change in entropy with change in temperature

Posted: Sun Feb 04, 2018 10:53 pm
by Kevin Ru 1D
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!