## Delta S equations

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

Miriam Sheetz 2B
Posts: 64
Joined: Fri Sep 28, 2018 12:25 am

### Delta S equations

Which delta S equations do we have to know for the midterm that are not on the equation sheet?

harshitasarambale4I
Posts: 58
Joined: Fri Sep 28, 2018 12:26 am

### Re: Delta S equations

One of the equations we need to know is...
delta S = -delta H/T

Raquel Ruiz 1K
Posts: 30
Joined: Tue Nov 14, 2017 3:02 am

### Re: Delta S equations

delta S(surrounding)= q(surrounding)/T which gives us delta S (surrounding) = -nRln(V2/V1) because q(surr)=w and w= -nRTln(V2/V1)

Albert Duong 4C
Posts: 66
Joined: Fri Sep 28, 2018 12:17 am
Been upvoted: 1 time

### Re: Delta S equations

delta S = nCpln(T2/T1) for constant pressure and delta S = nCvln(T2/T1) for constant volume. For the values of the heat capactities, Cp is (5/2)*R and Cv is (3/2)*R for ideal gas atoms or monatomic gases. Cp=(7/2)*R and Cv=(5/2)*R for diatomic gases such as nitrogen gas (these needed to be known to do some of the homework problems, but I'm not sure if they're going to be on the midterm).