Understanding Reversible Processes: Definition, Examples, and Importance

[phymatter]

A process is said to be reversible if the system and its surroundings are restored to their respective initial states by reversing the direction of the process. A reversible process has to be quasi-static

This is what my book says , but consider this :
i take something in an adiabatic container with a piston and pull up the piston to change its height by $$\Delta$$h in 1 step, then again I bring it back to same height in 1 step , now this process is not quasi-static but it has been reversed !
also it is back in the same state!

also why should the system be always in equilibrium to be reversable

 

[dE_logics]

The process will have to be accurate by 100%, that means the amount of work done on the system should be identical to the smallest amount of work done by the system...if you're measuring this, it's only achievable if you're observing the system by infinitely small steps, or making progress through infinitely small steps and each step is observed.

A smooth graph formed off the adiabatic process will mean that you have every infinity small detail proving that the area of the graph formed when work is done on the system = the area of the graph formed when work is done by the system...this is impossible in real life.

 

[charng]

?

I would like to clarify and expand upon the concept of reversible processes. While the definition mentioned in the content is accurate, it is important to understand that there are certain conditions that need to be met for a process to be truly reversible.

Firstly, as mentioned, a reversible process needs to be quasi-static, meaning that it needs to occur at an infinitesimally slow rate, allowing the system to continuously adjust to the changes happening. This is crucial because any sudden or abrupt changes can lead to irreversibility in the process.

In the example mentioned, where the piston is pulled up and then brought back down in one step, it may appear to be a reversible process as the system returns to its initial state. However, this process is not quasi-static and therefore not truly reversible. The sudden change in the height of the piston would not allow the system to adjust to the changes and may result in an increase in entropy, making the process irreversible.

Additionally, a reversible process requires the system to be in thermodynamic equilibrium throughout the entire process. This means that the system needs to be in a state of constant temperature, pressure, and composition. Any deviation from equilibrium can result in irreversible changes in the system.

In conclusion, while the concept of reversible processes may seem simple, it is important to understand the conditions that need to be met for a process to be truly reversible. Quasi-staticity and thermodynamic equilibrium are essential for a process to be reversible, and any deviation from these conditions can lead to irreversibility.