Midterm Question 6B

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

Katelyn 2E
Posts: 35
Joined: Sat Jul 22, 2017 3:01 am

Midterm Question 6B

Can anyone explain/provide their work for this question? For further reference, it is the one where 2/3 of the question was taken out and the one that remained was "under constant volume." How would you figure out moles for this question, too?

Kelly Kiremidjian 1C
Posts: 62
Joined: Fri Sep 29, 2017 7:04 am

Re: Midterm Question 6B

For this question I used the equation deltaS=nCvln(T2/T1)

You need to find the moles first, however using PV=nRT. Everything is given besides moles, so you can solve for n:
n=(1.00 atm)(53.48L)/(.08206)(303K) to get n=2.15 moles.

You can then use n to solve for change in entropy, using Cv as 3/2R because its constant volune:
deltaS=(2.15)(3/2)(8.314)ln (333K/303K)
and you should get deltaS=2.53 J x K-1

Hope this helps!