Irreversible and Reversible Processes

[Joanne Guan 1B]

I understand that a reversible process is one that can be reversed by an infinitely small change and an irreversible process is expansion against an external pressure that differs by a finite amount from the system's pressure. Can someone give examples for these two processes?

[Alexia Joseph 2B]

In class, the example Dr. Lavelle used was with two systems compressed with pistons.

Irreversible expansion: will have sudden expansion (results in a large change in volume)
Pressure of external atmosphere- 1 atm
Pressure of system- 2 atm


Reversible expansion: system will change slowly (results a very small change in V)
Pressure of external atmosphere- 1 atm
Pressure of system- 1 atm

[804899546]

So if the difference is that reversible reactions occur at equilibrium, what makes a reaction that occurs at non-equilibrium irreversible?

[Kevin Tabibian 1A]

An irreversible process would be as if I took a single 10g weight off of a balloon, allowing it to quickly expand. While a reversible process would be as if I individually removed from a balloon infinitely small weights that all collectively added up to 10g. The work in the second case would be much larger.

[504754253]

can someone explain what makes a reaction that occurs at non-equilibrium irreversible? and give an example