Thermodynamics - An Introduction to Physical Science


When we hear the word Thermodynamics from our teacher, we think of some behemoth concept that is going to take hours of study to understand it completely. Well, thermodynamics is a bit complicated; there is no doubt about it. But once you go through this article, you will understand the importance of thermodynamics and why you need to learn it as a science student. Once you understand the concepts of the thermodynamics, you will see how these laws are working in our daily lives and helping mankind to discover new things. Today we are going to talk about the laws of thermodynamics. The thermodynamics definition, along with chemical thermodynamics. So, clear up your mind and give us your full concentration because you need it to understand its concepts. 

Before we talk about the laws of thermodynamics, we first need to clear out the thermodynamics definition. The relationship of heat with the other forms of energy is the branch of science which is called thermodynamics. To be more precise, it is a study of thermal energy and how it is converted and how does it affect the matter when the conversion of the energy is taking place. 

Now talking about thermal energy, it is the energy present in the given substance due to its temperature—one of the thermodynamics examples which will show you what thermodynamics is in real life. The movement of the steam engine when the temperature gets high water becomes steam and makes the pistons to move. 

There are four main laws of thermodynamics, but in most cases, we only need the first three. In addition to this, the potential of molecular networks and every other minute detail of its design can be studied using thermodynamics. Likewise, It was first introduced as a theory that was entirely based on macroscopic phenomena such as temperature, pressure, volume along with energy. 

When two objects are in contact with each other. There is no transfer of heat and energy between them, and then you can say these two objects are in thermal equilibrium, this is the zeroth law of thermodynamics.

Laws Of Thermodynamics

Now, let's move to the three important laws of thermodynamics chemistry. 

The First Law of Thermodynamics 

This law in a lot of textbooks is also said to be the law of conversation of energy. This means energy can't be created, nor can it be destroyed by any means. As a result, energy gets converted to other forms.

In simple words, the first law states that whenever heat is being added in a system from the external source. Some of the energy stays with the system, and the rest of it gets consumed from work. The energy left in the system increases the internal energy. Internal energy is the total of your kinetic energy and potential energy. 

Isothermal process, Isobaric process, and Isochoric process are some of the applications of the first law of thermodynamics.

The Second Law of Thermodynamics 

"The total change in the entropy of any given system plus its surroundings will always make an increase in the spontaneous process," this is called the second law of the thermodynamics. Entropy in laymen's terms is said to be a measure of the randomness of a given system. Every system that you have around you wants to reach its maxim randomness and disorder. 

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(ice melts due to heat and forms water, providing second law of thermodynamics)

One great example of this law can be seen in your kid's room. Every time your mom cleans up your younger sibling's room after a few minutes, it will again become messy as toys will be thrown on the floor, and painting colours will come out from the drawer. Another example is the different states of liquid when in the solid form, ice, the molecules are tightly packed. On the other hand, when the ice melts and forms liquid, the molecules become disordered and random. 

Third Law of Thermodynamics 

"As the temperature around perfect crystal goes to absolute zero, its entropy also reaches to zero" this means thermal motion ceases and forms a perfect crystal at 0K. While there is any thermal motion found within the crystal at 0K, the atoms in the crystal will start vibrating, and it will lead to disorder, thus, violating the third law of thermodynamics. 

Application Of Thermodynamics

Every vehicle you drive or see on the road, sky, and even in the sea, all their engines are working based on the second law of thermodynamics. It doesn't matter if they are using petrol or diesel engine the laws will work in the same way.  

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(refrigerators usings laws of thermodynamics to keep food fresh during summertime)

Secondly, the refrigerators we have in our homes, deep freezers, and other air conditioning systems also work on the second law of thermodynamics. 

Lastly, all the compressors and the blower fans you see around you are using various thermodynamic laws and cycles to keep it working continuously.

FAQ (Frequently Asked Questions)

1. What is Thermodynamics in Chemistry?

Both head and work are said to be forms of energy and are related to each other. Such that, each of them can be transferred to the other. Physics is heavily based on the measurements of the mechanical events. Also, the changes that happen because of heat transfer and work comes in physical events, but they do have a chemical nature. Thus, thermodynamics in chemistry studies all these changes and measure their impact on the given substance or set of molecules. 

2. What is the Significance of Thermodynamics in Biochemistry?

One of the most important studies of biochemistry revolves around measuring the consumption rate of ATP. It is used to define a model of energy demand for cell growth, and here thermodynamics helps biochemists to find the required parameter accurately. 

Furthermore, thermodynamics also provides Gibbs energy dissipation limits along with mass balance and equilibrium constraints.