1. Content of Lecture 1:
"Thermodynamic Approach to States and Processes:
Concepts, Methods and Fundamental Results"
Prof. Javier Martínez Mardones
Instituto de Física

2. 1.1 Thermodynamics: The Science of States and Processes.
Targets and Areas of Study. Methodology and Philosophy.
Historical Background. Branches and Development of
Thermodynamics.
1.2 Energetics in Mechanics and the First Law of
Thermodynamics: A Summary of Key Points. Work and Kinetic
Energy. Potential Energy. Conservation of Mechanical Energy.
The First Law for Closed Systems. The Message of the First
Law. Consequences and Generalizations. Application: the
Enthalpy Function.
1.3 The Direction of the Natural Changes. Reversible and
Irreversible Processes.Heat Flow and Conversion of Work into
Heat. The Carnot Engine: Key Results. The Second Law.
Statements of Kelvin-Planck and Clausius. Equivalence. The
Message of the Second Law of Thermodynamics.

3. 1.4 Consequences of the Second Law. The Clausius
Theorem. Application to Reversible Cycles. Entropy
Difference between Two Equilibrium States. Application to
an Arbitrary Process. Differential forms of the Clausius
Theorem: Uncompensated Heat. Processes in a Closed
System with Defined Temperature. Applications: Heat
Reservoirs and Isolated Systems.
1.5 Entropy Change and Irreversible Processes.
Contributions to the Entropy Change. Entropy Production
and Entropy Flow.
The Second Law expressed as an Equality. Summary and
Remarks.

4. 1.1 THERMODYNAMICS: THE SCIENCE OF STATES
AND PROCESSES
1.1.1 Targets and Areas of Study
• The macroscopic properties of material systems.
• The Mechanical, Thermal and Chemical (MTC)
interactions between a system and another system
or its surroundings.
• The various processes of change in the macroscopic
properties of the systems.

5. 1.1.2 Methodology and Philosophy
• Experimental interrogation of nature. Acting on the
material systems and measuring the effects (the
answer of the system).
• The universe of operations of Thermodynamics: (a)
laboratory operations
• with macroscopic instruments and long time‑
measurements; (b) paper and pencil operations.
• Results: A few general statements, the Laws of
Thermodynamics. These are independent of the
theoretical models of the microscopic structure of
matter.

6. • These Laws summarize our knowledge of the
macroscopic behaviour of the real systems. In
particular, they capture two basic experiences: (a) The
existence of correlations between the results of
operations on macroscopic systems and (b) the
tendency of the systems to evolve towards rest and of
the changes to decay and "die out".
• On the basis of these Laws, new predictions can be
made. Key feature: interaction between theory and
experiments.

7. 1.1.3 Background
• Established as a discipline in the 1850's and 1860's.
• Context: Expansion of the experimental knowledge of
nature initiated in 1800. New phenomena and
connections between various phenomena. The idea of
the unity of nature.
• The problem of the efficiency of the heat engines.
Conversion of Heat into Work. The role of enginneering
concepts in the development of Thermodynamics.
• A long-standing problem: the kinetic nature of heat and
matter.

8. EquilibriumEquilibrium
Close to
Equilibrium:
Stationary
Close to
Equilibrium:
Stationary
Far from
Equilibrium
Far from
Equilibrium
Thermodynamics: Science of Status and processesThermodynamics: Science of Status and processes
States of the SystemStates of the System
Equilibrium
Thermodynamics
Equilibrium
Thermodynamics
Non-Linear
Irreversible
Thermodynamics
Non-Linear
Irreversible
Thermodynamics
Linear
Irreversible
Thermodynamics
Linear
Irreversible
Thermodynamics
ReversibleReversible
Transport and
some chemical
reactions
Transport and
some chemical
reactions
Various
Irreversible
Phenomena
Various
Irreversible
Phenomena
Processes Occurring in the SystemProcesses Occurring in the System

9. 1.1.4 Branches and Development of Thermodynamics
(I) Equilibrium States and Reversible Processes
(a) Classical Thermodynamics
Key names: Carnot, Mayer, Helmholtz, Joule, Clausius,
Thomson (Lord Kelvin).
Key issues and concepts:
• Systems and Surroundings.
• Efficiency of heat engines.
• Relations between Heat and Work.
• Energy and Entropy.

10. (b) Chemical Thermodynamics
Key names: Gibbs, Duhem, Van't Hoff, Nernst,
Le Chatelier, Lewis.
Key issues and concepts:
• Properties and States of Systems.
• Thermodynamic potentials.
• Physico-chemical equilibrium and stability.
• The direction of the physico-chemical processes
and reactions.

11. (II) Linear Irreversible Thermodynamics
Key names: de Donder, Bridgman, Eckart,
Tolman, Meixner, Onsager, Prigogine, de Groot,
Mazur.
Key issues and concepts:
• Entropy production.
• Affinities (Forces) and Rates (Flows).
• Phenomenological relations.
• Reciprocity relations.

12. (III) Non-Linear Irreversible Thermodynamics
Key names in the Local-equilibrium approach:
Prigogine and his school.
Key issues and concepts:
• Stability considerations.
• Evolution criteria.
• Fluctuations.
• Instabilities. Dissipative structures.

13. 1.2 ENERGETICS IN MECHANICS AND THE
FIRST LAW OF THERMODYNAMICS: A
SUMMARY OF KEY POINTS
1.2.1 Work and Kinetic Energy
1.2.2 Potential Energy
1.2.3 Conservation of Mechanical Energy
1.2.4 The First Law for Closed Systems
1.2.5 The Message of the First Law
1.2.6 Consequences and Generalizations
1.2.7 Application: the Enthalpy Function

14. 1.2.1 Work and Kinetic Energy

16. 1.2.2 Potential Energy

18. 1.2.3 Conservation of Mechanical Energy.
In the particular case of a Conservative System

20. 1.2.4 The First Law for Closed Systems

22. 1.2.5 The First Law for Closed Systems

24. 1.2.6 Consequences and Generalizations

26. 1.2.7 Application: The Enthalpy Function

29. 1.3 THE DIRECTION OF THE NATURAL CHANGE: THE
SECOND LAW
1.3.1 Reversible and Irreversible Processes.
1.3.2 The Carnot Engine: Key Results.
1.3.3 The Second Law: Classical Statements
1.3.4 The Message of the Second Law of Thermodynamics.

30. 1.3.1 Reversible and Irreversible Processes

31. 1.3.2 The Carnot Engine

32. 1.3.3 The Second Law: Classical Statements.

34. 1.3.4 The Message of the Second Law

36. 1.4 CONSEQUENCES OF THE SECOND LAW :
ENTROPY
1.4.1 The Clausius Theorem.
1.4.2 Application to Reversible Cycles: Entropy Difference
between Equilibrium States.
1.4.3 Application to an Arbitrary Process.
1.4.4 Differential forms of the Clausius Theorem:
Uncompensated Heat.
1.4.5 Processes in a Closed System with Defined
Temperature.
1.4.6 Applications: Heat Reservoirs and Isolated Systems.

37. 1.4.1 The Clausius Theorem

38. 1.4.2 Application to Reversible Cycles: Entropy Difference between
Equilibrium States

40. 1.4.3 Application to an Arbitrary Process

42. 1.4.4 Differential Forms of the Clausius Theorem: Uncompensated Heat

43. 1.4.5 Processes in a Closed System with a Defined Temperature.

45. 1.4.6 Application: Heat Reservoirs and Isolated Systems

48. 1.5 ENTROPY CHANGE AND IRREVERSIBLE
PROCESSES
1.5.1 Contributions to the Entropy Change
1.5.2 The Clausius Theorem Expressed as an Equality
1.5.3 Summary and Remarks

49. 1.5.1 Contributions to the Entropy Change

50. 1.5.2 The Clausius Theorem Expressed as an Equality

51. 1.5.3 Summary and Remarks

54. Content of Lecture 1:
"Thermodynamic Approach to States and Processes:
Concepts, Methods and Fundamental Results"
Prof. Javier Martínez Mardones
Instituto de Física