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Thermodynamic Relationships and Properties of Gibbs Energy

This text explores the relationships between thermodynamic properties and the Gibbs energy, including reversible and spontaneous processes, state functions, work calculations, and Maxwell's relations. It also covers the fundamental equations and properties of Gibbs energy. Homework problems and preview topics are included.

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Thermodynamic Relationships and Properties of Gibbs Energy

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  1. 1 2 4 3 100℃,PΘ 1mol, g 100℃,PΘ 1mol, l 30℃,PΘ 1mol, g 30℃,PΘ 1mol, l Can happen spontaneously or not (∆S)U,V≥0 Pending!

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

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

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

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

  6. C8H18(l)+25/2O2 8CO2(g)+9H2O Octane Application : Predict the available maximum work • CH4(g)+2O2 CO2(g)+2H2O Methane

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

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

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

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

  11. Related Coefficient equations State variation only

  12. The Maxwell relations T P V S

  13. =0 Circling relation equation Chain relations Inverse relations Other mathematical 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: P132-134: 5.11, 5.18, 5.31 • Preview: • A: 7.1-7.3 • Y:3.1-3.4 • 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.

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