Therdynamic Properties of Mixtures

Internal Energy

(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

(34.18)

Entropy

(34.19)

Specific internal energy of the mixture

(34.19)

or

(34.20)

mass fraction of species i

specific internal energy of species i

Molar internal energy of mixture

(34.21)

mole fraction of species i

molar internal energy of species i

Similarly we can write for specific enthalpy and molar enthalpy

and

(34.22)

We can also write for specific entropy and molar entropy

and

(34.23)

Change in u, h and s

	(34.24)

Assume remains unchanged

(34.25)

For ideal gas mixture

as is the same for all species as a result of thermodynamics equilibrium

or

(34.26)

Where definition of mixture

Similarly it can be shown that

(34.27)

Where

mixture (molar basis)

Let us also recall that and

We can also write similar relations for mixture enthalpy

(34.28)

Where

definition of mixture

and

(34.29)

Where

definition of mixture (molar basis)

Therefore, and . The equations are similar to the equations for a single (ideal gas) species.