Reversible process

[Karina Rahadian 2G]

The textbook states that a reversible process is "a process that can be reversed by an infinitesimal change in a variable." What are some examples of reversible and irreversible processes in thermochemistry? And what exactly counts as an infinitesimal change? Thanks!

[Brianna Bui 2J]

Hey!

I'm not completely sure on this topic, but I did some additional research and here is what I found.

a reversible process was defined as being able to be "turned back to such that both the system and the surroundings return to their original states, with no other change anywhere else in the universe." This is realistically impossible because we know that according to the second law of thermodynamics, the disorder of the universe increases with every reaction and energy is lost from a reaction system. So, truly reversible reactions with "infinitesimal change in a variable" are technically impossible and only exist in theory.
An example of such a reaction I found was slow isothermal compression or expansion of gases. This is to decrease the volume or increase the pressure while maintaining constant temperature and thus thermal equilibrium.

an example of irreversible reaction is a heat transfer.

Hope this helps!!

[Lizze Cardoso 2I]

Hi! A reversible process is when both the system and its surroundings can go from one state to another and return back to their original state. As mentioned above, a reversible process rarely happens, since it will be hard to restore both a system and its surrounding to their original state without adjusting the systems' surrounding. An example for a reversible process is the adiabatic process, in which heat does not enter nor leave, meaning that the system is always at equilibrium. An irreversible process is when the system and its environment cannot be restored to their initial state during the same time, as a reversible process would. An example of a irreversible process is heat transfer.

[Karina_Esqueda_2B]

A reversible process is a when system is at equilibrium but does more work and is a slower process. An irreversible process requires less energy than a reversible one and delta V changes slowly but small.