Therdynamic Properties of Mixtures
Internal Energy
![](images/image056.gif) |
(34.17) |
mass of species i
specific internal energy of species i
number of moles of species i
molar internal energy
Similarly we can write about Enthalpy
![](images/image066.gif) |
(34.18) |
Entropy
![](images/image068.gif) |
(34.19) |
Specific internal energy of the mixture
![](images/image070.gif) |
(34.19) |
or
![](images/image072.gif) |
(34.20) |
mass fraction of species i
specific internal energy of species i
Molar internal energy of mixture
![](images/image077.gif) |
(34.21) |
mole fraction of species i
molar internal energy of species i
Similarly we can write for specific enthalpy and molar enthalpy
and ![](images/image084.gif) |
(34.22) |
We can also write for specific entropy and molar entropy
and ![](images/image088.gif) |
(34.23) |
Change in u, h and s
![](images/image090.gif)
|
|
![](images/image092.gif) |
(34.24) |
Assume remains unchanged
![](images/image096.gif) |
(34.25) |
For ideal gas mixture
as is the same for all species as a result of thermodynamics equilibrium
or
![](images/image102.gif) |
(34.26) |
Where definition of mixture ![](images/image106.gif)
Similarly it can be shown that
![](images/image108.gif) |
(34.27) |
Where
mixture (molar basis) |
|
Let us also recall that and ![](images/image114.gif)
We can also write similar relations for mixture enthalpy
![](images/image116.gif) |
(34.28) |
Where
definition of mixture ![](images/image126.gif) |
|
and
![](images/image120.gif) |
(34.29) |
Where
definition of mixture (molar basis) |
|
Therefore, and . The equations are similar to the equations for a single (ideal gas) species.
|