Thermodynamics equilibrium with respect to matter flow

Click For Summary
SUMMARY

This discussion centers on solving a thermodynamics problem involving a movable partition between two chambers. The key equations include the entropy equation S = AU1/3V1/3N1/3 + (BN1N2)/N and the total energy equation Ut = [(A3/2V1/2)/(33/2)](Nr1/2 Tr3/2 + Nl1/2 Tl3/2). The user is tasked with finding the equilibrium temperature and volume, given specific conditions such as Tr = 2Tl = 400K. The challenge lies in adapting the solution from a rigid diathermic partition to a movable one, while maintaining constraints on volume, pressure, internal energy, temperature, and chemical potential.

PREREQUISITES
  • Understanding of thermodynamic principles, particularly entropy and energy equations.
  • Familiarity with the concepts of diathermic and rigid partitions in thermodynamics.
  • Knowledge of intensive and extensive properties in thermodynamic systems.
  • Ability to perform partial derivatives and analyze equilibrium conditions.
NEXT STEPS
  • Study the implications of movable partitions in thermodynamic systems.
  • Learn how to derive chemical potentials from internal energy equations.
  • Explore the application of the first and second laws of thermodynamics in equilibrium problems.
  • Investigate the role of intensive parameters in determining system behavior at equilibrium.
USEFUL FOR

This discussion is beneficial for students and professionals in thermodynamics, particularly those tackling equilibrium problems involving variable partitions. It is also relevant for educators developing problem sets in advanced thermodynamics courses.

kiyoshi7
Messages
7
Reaction score
0

Homework Statement


I don`t know if the image will show so I`m also adding a link to the image of the problem. This problem is a modification my professor made to the one in the link below(*), he changed the rigid diathermic partition into a movable partition. I`m supposed to find the equilibrium temperature and volume. He also mentioned that he isn`t sure that it can be solved, he kind of changed it spontaneously. Also sorry for the math, I don`t know how to format it here in the forums.

https://drive.google.com/open?id=18F64i9f9BeFHGuygQj4hpIK5yQjYzZPl
open

* taken from: thermodynamics and introduction to thermalstatistics vol. 2, Herbert B. Callen.

Homework Equations


S= AU1/3V1/3N1/3 + (BN1N2)/N
N = N1+N2
find equilibrium assuming the following
Tr = 2Tl = 400k
37B2 = 100A3V0

The Attempt at a Solution



I know how to solve it when the cylinder is separated by a rigid diathermic permeable partition, but I can`t figure out how deal with the movable partition in this problem. So I`ll describe the solution for the rigid partition.
first find the intensive parameters:
∂S/∂U = 1/T = (1/3)(AU1/3V1/3/N2/3)
∂S/∂N1 = -u1/T
then rewrite ∂S/∂U as U in function of temperature:
U = T3/2(A3/2V1/2N1/2)/(33/2)
Total Energy:
Ut= [(A3/2V1/2)/(33/2)]( Nr1/2 Tr3/2 + Nl1/2 Tl3/2 )
I imagine that here I`d do the same as I did with N and T ie: (V1/2l N1/2l T3/2l + V1/2r N1/2r T3/2r), But I can't figure out how to solve it after this
 
Physics news on Phys.org
kiyoshi7 said:

Homework Statement


I don`t know if the image will show so I`m also adding a link to the image of the problem. This problem is a modification my professor made to the one in the link below(*), he changed the rigid diathermic partition into a movable partition. I`m supposed to find the equilibrium temperature and volume. He also mentioned that he isn`t sure that it can be solved, he kind of changed it spontaneously. Also sorry for the math, I don`t know how to format it here in the forums.

https://drive.google.com/open?id=18F64i9f9BeFHGuygQj4hpIK5yQjYzZPl
open

* taken from: thermodynamics and introduction to thermalstatistics vol. 2, Herbert B. Callen.

Homework Equations


S= AU1/3V1/3N1/3 + (BN1N2)/N
N = N1+N2
find equilibrium assuming the following
Tr = 2Tl = 400k
37B2 = 100A3V0

The Attempt at a Solution



I know how to solve it when the cylinder is separated by a rigid diathermic permeable partition, but I can`t figure out how deal with the movable partition in this problem. So I`ll describe the solution for the rigid partition.
first find the intensive parameters:
∂S/∂U = 1/T = (1/3)(AU1/3V1/3/N2/3)
∂S/∂N1 = -u1/T
then rewrite ∂S/∂U as U in function of temperature:
U = T3/2(A3/2V1/2N1/2)/(33/2)
Total Energy:
Ut= [(A3/2V1/2)/(33/2)]( Nr1/2 Tr3/2 + Nl1/2 Tl3/2 )
I imagine that here I`d do the same as I did with N and T ie: (V1/2l N1/2l T3/2l + V1/2r N1/2r T3/2r), But I can't figure out how to solve it after this
It seems to me the constraints on this problem for the final state are:

The total volume is constant
The pressures in the two chambers are equal
The total internal energy is constant
The temperatures in the two chambers are equal
The chemical potentials of species 1 in the two chambers are equal. The chemical potential can be obtained by taking the partial derivative of U with respect to N1 at constant S and V.
 

Similar threads

  • · Replies 12 ·
Replies
12
Views
6K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
5
Views
3K
  • · Replies 16 ·
Replies
16
Views
2K
Replies
3
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
Replies
2
Views
2K