Chapter 2
Macroscopic Thermodynamics
This chapter introduces those aspects of thermodynamics directly of concern
to statistical mechanics. The natures of thermodynamic work and ‘heat’, the
roles of thermodynamic internal energy and entropy in formulating the laws
of thermodynamics, the concept of heat capacities, definitions of the various
thermodynamic state functions and their uses are discussed and illustrated. The
concepts of thermodynamic heat engines/refrigerators and their connections to
thermodynamic cycles should be of interest to those with engineering backgrounds.
Stability of isolated thermodynamic systems is addressed in terms of increases in the
system entropy associated with spontaneous irreversible processes. Multicomponent
systems and the roles played by the Gibbs energy and the chemical potentials for
the various components are investigated. The thermodynamics of real gases is
considered briefly, and illustrated in terms of the virial equation of state for model
Van der Waals fluids, two-phase regions, and the Joule–Thomson expansion.
Toward the end of Sect. 1.1 we referred to the thermodynamic internal energy U
without concerning ourselves with the meaning of the term ‘thermodynamic’. The
branch of experimental science that involves the study of the properties of bulk
continuum matter and the processes associated with changes in these bulk properties
is traditionally termed thermodynamics. Several definitive, and reasonably recent,
treatments of thermodynamics are available [1–4].
The main thrust of thermodynamics is to identify relationships amongst global
properties of macroscopic systems. In particular, the pressure, P , volume, V ,
temperature, T , and internal energy U are the most commonly encountered such
properties: in many cases they are also the most important properties of macroscopic systems. If a closed mathematical relation connecting the relevant global
macroscopic properties for a particular thermodynamic system can be obtained, it
is referred to as the equation of state pertaining to that system. Thermodynamics
is, in general, concerned with the utilization and conversion of energy, and
provides general restrictions on macroscopic (versus microscopic) energy transfers
© Springer Nature Switzerland AG 2021
F. R. W. McCourt, Statistical Thermodynamics for Pure and Applied Sciences,
https://doi.org/10.1007/978-3-030-52006-9_2
27
Macroscopic Thermodynamics
This chapter introduces those aspects of thermodynamics directly of concern
to statistical mechanics. The natures of thermodynamic work and ‘heat’, the
roles of thermodynamic internal energy and entropy in formulating the laws
of thermodynamics, the concept of heat capacities, definitions of the various
thermodynamic state functions and their uses are discussed and illustrated. The
concepts of thermodynamic heat engines/refrigerators and their connections to
thermodynamic cycles should be of interest to those with engineering backgrounds.
Stability of isolated thermodynamic systems is addressed in terms of increases in the
system entropy associated with spontaneous irreversible processes. Multicomponent
systems and the roles played by the Gibbs energy and the chemical potentials for
the various components are investigated. The thermodynamics of real gases is
considered briefly, and illustrated in terms of the virial equation of state for model
Van der Waals fluids, two-phase regions, and the Joule–Thomson expansion.
Toward the end of Sect. 1.1 we referred to the thermodynamic internal energy U
without concerning ourselves with the meaning of the term ‘thermodynamic’. The
branch of experimental science that involves the study of the properties of bulk
continuum matter and the processes associated with changes in these bulk properties
is traditionally termed thermodynamics. Several definitive, and reasonably recent,
treatments of thermodynamics are available [1–4].
The main thrust of thermodynamics is to identify relationships amongst global
properties of macroscopic systems. In particular, the pressure, P , volume, V ,
temperature, T , and internal energy U are the most commonly encountered such
properties: in many cases they are also the most important properties of macroscopic systems. If a closed mathematical relation connecting the relevant global
macroscopic properties for a particular thermodynamic system can be obtained, it
is referred to as the equation of state pertaining to that system. Thermodynamics
is, in general, concerned with the utilization and conversion of energy, and
provides general restrictions on macroscopic (versus microscopic) energy transfers
© Springer Nature Switzerland AG 2021
F. R. W. McCourt, Statistical Thermodynamics for Pure and Applied Sciences,
https://doi.org/10.1007/978-3-030-52006-9_2
27