Reversible Process
An idealised process carried out through a continuous series of equilibrium states, so it can be reversed by an infinitesimal change.
Formula / equation
w_rev = −∫p dV
Unit
J
In depth
A reversible process is infinitely slow and leaves no net change in the universe when reversed, which is why it delivers the maximum possible work and creates no entropy. It is a theoretical limit rather than a practical procedure, but it provides the benchmark against which real processes are measured.
Examples in the real world
A gas expanding against a pressure lowered grain by grain; ice melting exactly at 0 °C.