Entropy Chapter 9 #7


Moderators: Chem_Mod, Chem_Admin

Jonathan Orozco 1A
Posts: 9
Joined: Wed Sep 21, 2016 2:58 pm

Entropy Chapter 9 #7

Postby Jonathan Orozco 1A » Wed Jan 25, 2017 7:42 pm

Hello everyone i was wondering any one could send me in the right direction as to which formula to use for question #7 chapter 9.

Question #7: Assuming that the heat capacity of an ideal gas is independent of temperature, calculate the entropy change associated with raising the temperature of 1.00 mol of ideal gas atoms reversibly from 37.6 C to 157.9 C at (a) constant pressure and (b) constant volume.

Thank you in advance, and have a great day!

Daniel Dobrin 2F
Posts: 12
Joined: Sat Jul 09, 2016 3:00 am

Re: Entropy Chapter 9 #7

Postby Daniel Dobrin 2F » Wed Jan 25, 2017 10:25 pm

You would use basically the same formula for both parts of the question.
For constant pressure, use:
Delta S = n*Cp*ln(T2/T1), where Cp signifies a constant pressure.

For constant volume, use:
Delta S = n*Cv*ln(T2/T1), where Cv signifies a constant volume.

Since it tells us we're dealing with ideal gas atoms, we're gonna change the Cp and Cv. On the formula sheet, it says that for monatomic ideal gases, Cp = 5/2*R and Cv = 3/2*R, where R is the gas constant (8.314 J/K/mol).

Hope this helps! :)

Return to “Entropy Changes Due to Changes in Volume and Temperature”

Who is online

Users browsing this forum: No registered users and 1 guest