1. ∆U=Q+W
S, A, G

2. T, P, V A
CP, CV
U, H, S, A, G A’
Closed system
State variation

3. The drive force ? ? Equilibrium A Nonequilibrium
Direction of variation and the limitation
The drive force ? A B
How to judge?
What could be got from the variation? Q, W, Wf

4. The justification at constant temperature and pressure
Phase variation
liquid
gas
water
G(l)
G(g)
δmol, Water(Liquid) ↔Water (Gas)
Phase equilibrium:
Phase variation direction:
For chemical reaction:

5. Phase transformation or reaction: AB
G = GB – GA
The variation of the Gibbs energy with pressure at constant temperature
The variation of the Gibbs energy with temperature at constant pressure
Gibbs-helmholtz equation

6. Example 1: 1/2N2+3/2H2 NH3 25℃,PΘ: 600℃,PΘ: 25℃,10PΘ:
Gibbs-helmholtz equation
600℃,PΘ:
25℃,10PΘ:

7. Example 2: Diamond Graphite 25℃,Py Smy/JK-1  mol-1 CHmy/kJmol-1
 /g  cm-3
C(graphite)
5.6940 –
2.260
C(diamond)
2.4388 –
3.513
How about increase temperature?
1000℃, p0:
How about increase pressure?