Branches of Thermodynamics

Thermodynamics is the study of thermal, electrical, chemical, and mechanical forms of energy. The study of thermodynamics crosses many disciplines, including physics, engineering, and chemistry. Of the various branches of thermodynamics. 

Psychrometrics. Psychrometrics is the branch of thermodynamics that deals specifically with moist air, a biaary mixture of dry air and water vapor. The properties of moist air are frequentiy presented on psychrometric charts such as that shown ia Figure 2 for the normal air conditioning range at atmospheric pressure. Similar charts exist for temperatures below 0°C and above 50°C as well as for other barometric pressures. AH mass properties ate related to the mass of the dry air. 

So far in this chapter our discussion has focused on thermochemistry, the study of the heat effects in chemical reactions. Thermochemistry is a branch of thermodynamics, which deals with all kinds of energy effects in all kinds of processes. Thermodynamics distinguishes between two types of energy. One of these is heat (q) the other is work, represented by the symbol w. The thermodynamic definition of work is quite different from its colloquial meaning. Quite simply, work includes all forms of energy except heat. 

Thermochemistry is the branch of thermodynamics concerned with the way energy is transferred, released or consumed during a chemical reaction. 

These arguments represent a simple example of phase equilibria. This branch of thermodynamics tells us about the direction of change, but says nothing about the rate at which such changes occur. 

The study of energy and energy transfer is known as thermodynamics. Chemists are interested in the branch of thermodynamics known as thermochemistry the study of energy involved in chemical reactions. 

Al(s) + Fe203(s) —> Al203(s) + 2Fe(l). thermochemical equation An expression consisting of both the balanced chemical equation and the reaction enthalpy for the chemical reaction exactly as written, thermochemistry The study of the heat released or absorbed by chemical reactions a branch of thermodynamics. 

The branch of thermodynamics known as the thermodynamics of reversible processes is actually a study of thermodynamic systems at equilibrium, and it is this branch that is so important in the application of thermodynamics to chemical systems. Starting from the fundamental conditions of equilibrium based on the second law, more-practical conditions,... 

At this point the need arises to become more explicit about the nature of entropy generation. In the case of the heat exchanger, entropy generation appears to be equal to the product of the heat flow and a factor that can be identified as the thermodynamic driving force, A(l/T). In the next chapter we turn to a branch of thermodynamics, better known as irreversible thermodynamics or nonequilibrium thermodynamics, to convey a much more universal message on entropy generation, flows, and driving forces. 

Thermochemistry is a branch of thermodynamics that deals with the change of heat (enthalpy) in chemical reactions. The heat absorbed or lost in chemical reactions usually occurs at constant pressure rather than at constant volume. The change of heat is mostly expressed by AH, the enthalpy change of a process from reactants to products ... 

Mechanical work manifests itself into displacement of a body under mechanical force such as accomplished in heat engines. For example, steam locomotives perform mechanical work. Study of such processes has lead to one particular branch of thermodynamics, which is commonly referred to as Thermodynamics Applied to Heat Engines or Mechanical Engineering Thermodynamics or simply Engineering Thermodynamics. ... 

Matters are made up of small particles such as molecules and atoms. Thermodynamic laws have been postulated and inferred without looking into the micro-properties or microstates within the systems. A branch of thermodynamics has evolved, which tries to interpret thermodynamic properties based on the properties of micro constituent of the system. This branch is called the Statistical Thermodynamics. An offshoot is the Nuclear Thermodynamics , where matter is treated as another form of energy and role of atomic and subatomic particle forms are studied in determining thermodynamic properties. 

Development of the subject of thermodynamics, as the readers might have noted, has been based on facts, some commonly observed facts, while others have been experimentally determined findings. These observations of facts have been at macrolevels, and have been summarised into the different laws of Thermodynamics. While the applicability of these laws at micro level can be a matter of debate, but logically the thermodynamic properties of the system determined at macro level, should be derivable from the properties of particles constituting the system. The method and principle behind this derivation forms the basis of Statistical Thermodynamics - a special branch of thermodynamics. 

Example of a reversible transformation fumidied by the vaporization of a liquid.—This idea of reversible transformation is of great importance in all branches of thermodynamics one can-... 

The study of solutions and their properties is one of the important branches of thermodynamics. It is important to know the behavior of a mixture of components for a change in temperature, pressure, and composition. Knowledge in this area of thermodynamics helps engineers... 

The importance of this new state function, enthalpy, will become apparent when we study thermochemistry, the branch of thermodynamics concerning the heat changes associated with chemical reactions. For the moment let us note that when we see... 

In conclusion to this introduction it may be remarked that a new branch of thermodynamics has developed during the past few decades which is not limited in its applications to systems at equilibrium. This is based on the use of the principle of microscopic reversibility as an auxiliary to the information contained in the laws of classical thermodynamics. It gives useful and interesting results when applied to non-equilibrium systems in which there are coupled transport processes, as in the thermo-electric effect and in thermal diffusion. It does not have significant applications in the study of chemical reaction or phase change and for this reason is not included in the present volume.f... 

Thermodynamics is the study of energy and its transformations, and two chapters in this text address this central topic. Our focus here is on thermochemistry, the branch of thermodynamics that deals with heat in chemical and physical change. 

The description of state behaviour of real gases and their mixtures is an extensive branch of thermodynamics. It is not practically possible (neither would it be purposeful) to attempt a detailed discussion of the topic, the more as it has been treated in several outstanding publications in great detail. Since highly complex, multi-component systems must be expected to originate in calculations of chemical equilibria, where the state behaviour in dependence on composition of the mixture usually is not known, it seems to be useful to limit the discussion to the determination of the real behaviour of mixtures from the known properties of their pure constituents. 

Thermodynamics is the study of the conversions among different types of energy. Thermochemistry is a branch of thermodynamics. 

These problems lead to the second major branch of thermodynamics, which we will now formulate. It deals only with equilibrium systems. It should be pointed out that this branch still uses the same observations of nature (conservation of energy and directionality) that we have already studied. In these problems, however, we wish to calculate how species distribute among phases when more than one phase is present (phase equilibria) or what types of species are formed and how much of each type is produced as systems approach equilibrium when the molecules in the system chemically react (chemical reaction equilibria). We will consider phase equilibria first. These calculations are restricted to equilibrium systems therefore, they give information on the direction of the driving force for a given system (i.e., the system will spontaneously move toward its equilibrium state) but no information on the rate at which it will reach equilibrium. 

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