How to visualize entropy in thermodynamics

Click For Summary
Entropy is fundamentally a measure of disorder, but visualizing it in practical terms can be challenging, especially when considering the behavior of numerous particles. The relationship between entropy and the number of macrostates is expressed through Boltzmann's equation, S = k ln W, where W represents the number of accessible microstates. To prove this relationship using statistical mechanics, one must understand the connection between entropy and temperature, as well as how to calculate the number of macrostates. The discussion emphasizes the importance of using the thermodynamic definition of entropy, dS = dQ/T, to clarify these concepts. Overall, grasping these principles can enhance the understanding of entropy in thermodynamics.
vijay123
Messages
122
Reaction score
0
entropy is the measure of disorder...but i just cannot visualize it in a practical standpoint...i mean...the disorder taking place with soo many particles when heated and yet all i know is that s=q/t...can anyone explain this concept better to me?

one more question...how does one prove using statistical mechanics that
s=(boltzmann's constant)lnw...were w is the number of macrostates...

i was tryng to do calculus based entropy probelms...but can do them in refrence to s=(boltzmann's constant)lnw, by counting the number of macrostates available??

and is it possible to find th number of macrostates by equating (boltzmann's constant)lnw=q/t...is this a very large number?
 
Physics news on Phys.org
vijay123 said:
one more question...how does one prove using statistical mechanics that
s=(boltzmann's constant)lnw...were w is the number of macrostates...
Entropy of a composite system is given by:
S* = SA + SA'-----(1)
Number of accessible states to A* is:
W* = WAWA'------(2)

S*,SA, SA' are entropies of composite system A*, A and A' respectively(A* composed of A and A').
The entropy is a "state" function.
For (1) & (2) to hold good simultaneously, what should be the nature of this function?
 
W in S=klnW is the number of microstates.

I was indtroduced to entropy through S=klnW as the definition, therefore it's not provable. What definition of S do you use??
 
vijay123 said:
entropy is the measure of disorder...but i just cannot visualize it in a practical standpoint...i mean...the disorder taking place with soo many particles when heated and yet all i know is that s=q/t...can anyone explain this concept better to me?

one more question...how does one prove using statistical mechanics that
s=(boltzmann's constant)lnw...were w is the number of macrostates...

i was tryng to do calculus based entropy probelms...but can do them in refrence to s=(boltzmann's constant)lnw, by counting the number of macrostates available??

and is it possible to find th number of macrostates by equating (boltzmann's constant)lnw=q/t...is this a very large number?
Use the thermodynamic definition of entropy and forget about the concept of disorder: dS = dQ/T

AM
 
You'll need to use the definition of temperature \frac{1}{k_{B}T} = \frac{\partial\ln\Omega}{\partial U} as well.
 
...though you might want to show where that comes from, it might be kinda easy otherwise...
 

Similar threads

  • · Replies 18 ·
Replies
18
Views
6K
Replies
4
Views
5K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
4
Views
9K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 3 ·
Replies
3
Views
9K
  • · Replies 7 ·
Replies
7
Views
3K