|
TdS Equations
- For a closed system contaning a pure compressible substance undergoing a reversible process.
![](images/image124.gif)
|
(24.22) |
or (per unit mass) |
(24.23) |
This is the famous Gibbsian equation.
- Eliminate du by using the definition of enthalpy
![](images/image132a.gif)
![](images/image134.gif) |
(24.24) |
Thus,
![](images/image136.gif) |
(24.25) |
![](images/image138.gif) |
(24.26) |
Also,
![](images/image140.gif) |
(24.27) |
- Important: These equations relate the entropy change of a system to the changes in other properties :
. Therefore, they are independent of the process .
These relations can be used for reversible as well as irreversible processes.
|