1. (∆S)U,V≥0 Pending! Can happen spontaneously or not 1 2 4 3 1mol, g
1mol, l
1mol, g 1
100℃,PΘ 2 3 4
Can happen spontaneously or not
Pending!

2. 3.8 Helmholtz / Gibbs energies and their applications
Helmholtz free energies
work function
Helmholtz Justification
=, equilibrium(reversible); <, spontaneous

3. Gibbs energies Remark Gibbs free energy Gibbs justification ΔPTG=0
Reversible phase shift
ΔPTG=0
Gibbs free energy
Gibbs justification
=, equilibrium(reversible); <, spontaneous

4. Understanding about A and G State function Variation driving force Energy---Work function

5. Calculation of ΔA and ΔG
Due to
Calculating work
A=U-TS G=H-TS
Due to calculating ΔU,ΔH,ΔS
relating
ΔH<<0
ΔS>>0
ΔG<0
ΔH<0 ΔS>0
Q, W, ΔU, ΔH, ΔS, ΔA, ΔG

6. Application : Predict the available maximum work
CH4(g)+2O CO2(g)+2H2O Methane
C8H18(l)+25/2O CO2(g)+9H2O Octane

7. 1mol supercooled water get frozen at 268K and 101325 Pa, the Wf,max, Wmax?
H2O(l),268K, Pa
H2O(S),268K, Pa
H2O(l),273K, Pa

8. Predict the reaction direction
Helmholtz
Gibbs
Clausius Justification
100℃,PΘ
1mol, l
1mol, g
To vacuum
free
W=0
25℃,PΘ
1mol, l
1mol, g
ΔG=8285J > 0

9. U, H, S, A, G, CP, CV, T, P, V 3.9 Thermodynamic relationships
Ten functions
U, H, S, A, G, CP, CV, T, P, V
All state functions
Closed system, no phase transformation, no chemical reaction, no composition change, 2 independent parameters
Characteristic functions
----Massieu
Z: H, S, A, G …..

10. The fundamental equations Definitions
W’=0
Closed system
Wf=o

11. Related Coefficient equations
State variation only

12. The Maxwell relations
T P
V S

13. Other mathematical relations
Circling relation equation =0
Chain relations
Inverse relations

14. Heat capacity relations

15. 3.10 Properties of the Gibbs energy G(T, P, V)
State variation
Phase transformation or reaction:AB: G = GB – GA

16. Homework: Y: P76: 23, 25, P77: 28; P79: 33 P80:37
A: P : 5.11, 5.18, 5.31
Preview: A: Y:
Group discussion:
I: Approaches to decrease greenhouse gas and save energy.
II: Understanding about the orderly assembly phenomenon in nature( entropy principle)
III: Where would the world go? Introduction about the dissipative structure principle.