Thermodynamics Classification And Approaches

Thermodynamics is the branch of physics that studies the interaction of heat and other types of energy. It explains how thermal energy is turned into other forms of energy in particular. The study of how heat moves from a hot object to a cool object is an example of thermodynamics. 

Thermodynamics is the foundation for heat engines, power plants, chemical reactions, freezers, and a variety of other significant concepts in today's society.

For Examples; 

Water flows spontaneously from higher level to lower level, Hot coffee become cold coffee after some time, Melting, Freezing, Sublimation, Electric light bulb(electric energy is converted into light energy), Radiator, heat engine, Heat pump, Refrigerator, etc.

In this article, we will learn about the classification of thermodynamics & approaches made in thermodynamics to find out the thermodynamic properties of matters.

Classification of Thermodynamics

There are mainly four types of thermodynamics namely;

(1)Classical Thermodynamics

(or general thermodynamics that describe the behaviour of a system at microscopic level) 

Classical thermodynamics uses macroscopic, quantifiable features to describe the states of thermodynamic systems in near-equilibrium. It is used to simulate energy, work, and heat exchanges using thermodynamic laws.

(2) Statistical Thermodynamics

(describe the behaviour of a system at macroscopic level)

(3) Pure component Thermodynamics

(describe the behaviour of a system that has a pure constituent)

(4) Solution Thermodynamics

(describe the behaviour of a system that contains more than one chemical in a mixture or solution.)

Types Of Approaches

There are two approaches or points of view for studying the behaviour of matters or for describing the thermodynamic systems in order to calculate the thermodynamic properties of that matter. These are;

1. Microscopic Approach
2. Macroscopic Approach

As we know that a substance is composed of a large number of molecules and the properties of the substance is depending on the behaviour of these molecules. 

Hence, 

"The thermodynamic behaviour of matter is investigated either with a microscopic or macroscopic approach".

(1) Microscopic Approach

In this, we study the thermodynamic behaviour of a matter at a molecular or atomic level (or we study the average behaviour of molecules constituting the matter). Therefore, we need a large number of variables to describe the thermodynamic behaviour of matter. And when we use the microscopic approach in thermodynamics, the subject we get is called "Statistical thermodynamics". 

Properties such as velocity, kinetic energy, impulse and momentum will be studied and determined on the basis of microscopic approach.

(2) Macroscopic Approach

"When we study the thermodynamic behaviour of a matter without considering the event happening at molecular level (or when we describe the behaviour of matter at a general level), then it is called as macroscopic approach". Therefore, we need very less number of variables to describe the behaviour of a matter. This approach requires simple mathematical formulas for analysing the thermodynamics behaviour of matter. And when we use the macroscopic approach in thermodynamics, the subject we get is called "Classical thermodynamics".

Macroscopic effects i.e. average effects could be easily analysed by human sense or by measuring instruments such as pressure and temperature. 

With the use of measuring devices or human sense, pressure and temperature may be easily determined.

➛ Classical Thermodynamic------Macroscopic Approach

➛ Statistical Thermodynamic------Microscopic Approach

Even both approaches are seem to be different but when both approaches will be applied over a particular system then both approaches will provide the similar result.

The Aim Of Thermodynamics?

Its basic aim is to convert disorganised form of energy that is Heat into organized form of energy that is Work.

Energy is available all around you. It is actually disorganised and that is the reason we say the net entropy of the universe is increasing.

And thus Thermodynamics plays its role here by converting this disorganised form of energy into organized form of energy i.e work by which we can run various machines like pumps etc.

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