Reversible vs Irreversible

[Jasmine Alcantara 3G]

Can anyone give me examples of a reversible and an irreversible process that haven't been mentioned in class? I can't seem to properly wrap my head around the processes.

[kane_jajieh_3F]

An example of a reversible reaction would be
when you have a cylinder with a piston. And this container is filled with gas. now when this gas pushes on the piston it does work. The work this gas does on the piston is defined as reversible when the resistance the gas faces is always equal to the force the gas is pushing on it. So as the gas does work it loses energy and pushes less hard. As the gas starts to push less hard so does the resistance it faces. all then way until the gas can do no more work.

and an irreversible reaction is when the resistance the gas faces is a constant pressure say 1 atm. So the gas will only move the piston if its pressure is greater than one atm. and when the gas does work on the piston and loses enough energy and its pressure goes lower than 1 atm. the gas will do no more work on the piston.