Introduction to Thermodynamics

1
Introduction to Thermodynamics
2
(No Transcript)
3
U internal energy
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
Entropy
P
P / 2
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(Craig Counterman)
16
J g-1 K-1 at 300 K
atomic number
(Craig Counterman)
17
(No Transcript)
18
Allotropic Transition
19
Q Why is Gibbs free energy called free?
A Because it is that part of the energy which is
in principle obtainable as mechanical
work. N. K. Adam, Physical Chemistry,
Clarendon Press, Oxford (1956) page 263.
20
(No Transcript)
21
Allotropic Transition in Pure Iron
22
Mechanical Mixture
free energy of
mechanical
o
m
mixture
B
G
o
m
Gibbs free energy per mole
A
x
1-x
A
B
Concentration x of B
23
entropy is a capacity property, like mass, energy
etc. Different entropies can be added S1S2S3
How does this fit with the probability picture?
24
Entropy
P
w1
wvery large
P / 2
25
w is not a capacity property of the system. For
example, the chance of throwing two sixes with
dice is (1/6)2, not 1/61/6. Boltzmann realised
that we should use lnw and not w to meaure
disorder.
26
(No Transcript)
27
free energy of
mechanical
o
m
mixture
B
G
Gibbs free energy per mole
o
m
A
?G
M
Gx
free energy
of solution
A
B
x
Composition
28
o
m
B
o
m
Gibbs free energy per mole
A
Gx
A
B
x
Composition
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
Binary solution
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
(No Transcript)
40
(No Transcript)
41
(No Transcript)
42
(No Transcript)
43
(No Transcript)
44
(No Transcript)
45
(No Transcript)
46
Irreversible Processes Steady State
47
dissipating free energy
48
Process whose direction can be changed by an
infinitesimal change in external conditions is
reversible.
49
(No Transcript)
50
Process which dissipates energy is irreversible
to an infinitesimal change in external conditions.
51
(No Transcript)
52
(No Transcript)
53
(No Transcript)
54
(No Transcript)
55
(No Transcript)
56
(No Transcript)
57
(No Transcript)
58
(No Transcript)
59
(No Transcript)
60
(No Transcript)
61
(No Transcript)
62
(No Transcript)