Introduction To Thermodynamics

The science of thermodynamics was born in nineteenth century

Introduction 
Thermodynamics means the study of heat in motion. Let me explain to you how;
The word thermodynamics is made of two Greek words - "Therme + Dynamic"
               Therm means Heat
         Dynamic means work/power/Motion
Thus, in a simple way;
"Thermodynamics is nothing but a study of heat in motion (or heat movement or heat flow)".
Or
"Thermodynamics is the science that studies the transition of heat into work and work into heat".
Or
"Thermodynamics is a branch of physics that studies equilibrium states and the link between energy and work". 

Let me give you some examples to give you a feel of the concept of thermodynamic;
1) What happens when you heat one end of a metallic rod?
When one end of the metallic rod is heated, the other end also gets heated within a few minutes. Have you ever experienced this? 
This is because of heat flow from one end to another end in a metallic rod.
2) What happens when you keep the hot coffee in the room?
It will cool down gradually and achieves room temperature. This is because of heat flow from high temperature to low temperature.
3) What happens when you keep on applying heat to the water?
The water gets heated and finally, it starts to boil. This is related to thermodynamics.
➛ All these things occur due to thermodynamics. 

Thus, one of the most important concepts of Thermodynamics is "Transfer Of Heat".
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, the working of Refrigerators, Air Conditioners, Exhaust Systems, automobiles etc. are applications of Thermodynamics.

Thermodynamics Can Be Defined In A Variety Of Ways, For Example;
The definitions of thermodynamic can be stated as;
(1) Thermodynamics is the science that deals with the relationship between heat and other forms of energy. In particular, it tells us that how thermal energy is converted into other forms of energy and how it affects the matter.
(2) Thermodynamics is the study of heat and temperature and their relation to the energy and work. 
(3) Thermodynamics is the branch of science that deals with the study of energy and the conservation of energy between different forms and the availability of energy to do work.
(4) Thermodynamics is the study of the effects of work, heat and energy on a system.
(5) Different forms of energy are related to each other under particular circumstances. and can be changed from one form to another. The study of these energy-transformations is the subject matter of thermodynamics.
(6) Thermodynamics is the science of energy intersection (mainly heat to work and work to heat) and their effects on the physical properties of the matters.
( Matter can be of solid, liquid and gas)
( Physical properties are those properties that can be observable by human senses like by eyes, by touch etc. )
(7) The most famous definition of thermodynamics is that thermodynamics is the study of three E's and these are - Energy, Entropy and Equilibrium.
 
NOTE
☛ Through thermodynamics, we can also answer some important questions. 
For Example 
1) How do you determine the energy change in a chemical process? 
2) Will this change occur or not? 
3) How is a chemical process induced? 
4) And to what extent does the chemical reaction last?
Thus, thermodynamics tells us whether a reaction is possible or not. The main aim of thermodynamics is to determine the efficiency of the engines. This information is very important for an engineer to design the efficient engines.

☛ The concept like "ANOMALOUS EXPANSION OF WATER" in Thermodynamics is extremely useful to understand how the aquatic life is surviving in colder regions like Artic and Antartica.
Explanation of anomalous expansion of water:
Density of water is maximum at 4°c.When the water reaches at 0°c,ice is formed .This ice floats at top of the water and aquatic life survives in water (1°c-4°c) below that ice.If this process doesn't happen,the entire aquatic life would be vanished in cold regions where ice freezes.


Importance Of Thermodynamics
Thermodynamics is usually involved in analysis of almost all the engineering problems. Thermodynamics is important because,
  1. It tells us whether a reaction is actually possible or not under specified conditions.
  2. It tells us that how energy is transferred
  3. It gives a framework to predict the behaviour of matter
  4. Used to predict the extent of reaction
  5. To derive important laws like law of equilibrium.
  6. Dealing with energy changes in physical and chemical processes.
  7. Thermodynamics science tell us about the direction of change (means the changes occur in which direction like the direction of change in water level, direction of change of heat etc.)


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