Reversible and Irreversible Processes

You often do not acknowledge several physical, chemical and other changes happening around you. Some of these processes cannot even be felt, with their existence often eluding you. However, these processes do occur and there is a difference in the state of the participants taking part in these processes. 


For instance, boiling of water, melting of ice, burning of things, etc. All these are processes that are distinct in nature, although, in all of them, one aspect is common. There is an exchange of heat or energy in each case, and they can be classified under reversible and irreversible processes. 


What is a Reversible Process?

As the name suggests, a reversible process is one that can be reversed to its initial state even after the process is completed. In simple words, let us take an example like that of melting ice and vice versa. Here, water is initially in the liquid state, which freezes to form ice, while on heating this ice, it melts back to give water.


Students should note that a reversible process takes two processes into account. While in the first process participants convert into another form, in the case of this second process the reverse reaction takes place where the resultants get back to the initial stage.


Hence, understanding this will help in further delving into the difference between reversible and irreversible process. You should also note that understanding these processes is not just vital for your Physics curriculum, but also that of chemistry.


What is an Irreversible Process?

To understand this, consider a reversible process example - the cooking of food. You begin by arranging the necessary ingredients - vegetables, spices and meat and cook the entire thing and prepare a dish. Now, however hard you try, you cannot get back the ingredients in their original form. Another fine example is that of fuel consumption where once converted into energy, the process cannot be reversed to get back the fuel.

They have already been turned into something new which possess a completely different set of properties. Yet another crucial aspect that comes here is that the participants lose their individual characteristics in an irreversible process. 


Therefore, students should be cautious while studying both reversible process and irreversible process. Each process or method should be carefully analysed so as to understand its type. 


Reversible and Irreversible Process in Thermodynamics

In terms of thermodynamics, a reversible process is where the participants go back to its initial form by inculcating minor or negligible changes in their surroundings. Contrarily, an irreversible process is a naturally occurring phenomenon, which does not go back to its original state. 


Students should be able to tell the difference between reversible and irreversible process in thermodynamics only when they have built an understanding of the same. 

Factors behind Irreversibility of a Process.


The Reversible Nature of a Process is Dependent on Multiple Factors Such as -

  • Non-elasticity

  • Friction

  • Viscosity

  • Electrical resistance

  • Magnetic resistance or hysteresis


As a student, it is important you have an idea of the various criteria for reversible and irreversible process. 


To know more about what is reversible and irreversible process, check our online learning programmes for an in-depth understanding. You will get access to high quality lessons that will help you in building these vital concepts from their grassroot level.


You can even get your learning materials on our Vedantu app where we explain reversible and irreversible process and every other necessary concept in the most detailed manner.

FAQ (Frequently Asked Questions)

1. What is the Reversible and Irreversible Process Definition?

Ans. A reversible process is where the ingredients can get back to their original state after completion of the process. On the other hand, an irreversible is precisely the opposite, where the elements do not come back to their original state. Take an example of reversible and irreversible process each for better understanding - meting of ice and burning of paper, respectively.

2. Define the Quasi-Static Process?

Ans. In scientific terms, an irreversible process is said to be in quasi-static mode, wherein the change is likely to be occurring at a highly slow rate. The rate of change is so slow that it seems to be in equilibrium at all times.

3. What do you mean by Free Expansion?

Ans. The phenomenon of free expansion is said to occur in a gas such that the gas escapes into space without doing any work. In simple words, there is no heat or energy lost in this reversible process.