文档介绍：Chapter 10
Nonideal Solutions
Physical Chemistry
1
Ideal Solutions
Solutions
B at T, P
C at T, P
B + C at T, P
B-B, C-C
B-B, C-C,
B-C
Physical Chemistry
If B-B, C-C and B-C interactions are all different
2
Nonideal Solutions
Solutions
B at T, P
C at T, P
B + C at T, P
B-B, C-C
B-B, C-C,
B-C
Physical Chemistry
If B-B, C-C and B-C interactions are all different
The molecules of one type cluster together
anization of the molecules: orderly mixture
Separation is spontaneous
Liquids e immiscible or partially miscible
3
The chemical potential () does more than show how G varies position.
The Wide Significance of Chemical Potential
Nonideal Solutions
A general infinitesimal change in U for a system of position can be written
At constant V and S
Physical Chemistry
4
The Wide Significance of Chemical Potential
Nonideal Solutions
hence
In the same way, it is easy to deduce
Physical Chemistry
5
Activity and Activity Coefficients
Nonideal Solutions
()*
ideally dilute solution
()*
ideally dilute solution
ideal solution
()*
ideal solution
()*
ideal or ideally dilute solution
()*
ideal or ideally dilute solution
()
Physical Chemistry
6
Activity and Activity Coefficients
Nonideal Solutions
ideal or ideally dilute solution
()
When the solution is neither ideal nor ideally dilute solution,
every solution
()
ai is defined as activity, a kind of “effective” mole fraction.
every solution
()*
The difference between and
Physical Chemistry
7
Activity and Activity Coefficients
Nonideal Solutions
The ratio is the measure of the departure from ideal behavior.
every solution
()*
activity coefficient
The activity coefficient i measures the degree of departure of substance i’s behavior from ideal or ideally dilute behavior. The activity ai is obtained from the mole fraction xi by correcting for nonideality.
Physical Chemistry
8
Activity and Activity Coefficients
Nonideal So