Difference between reversible and irreversible expansion?

[Beatrice Petelo 1F]

Hi!

Can someone please explain the difference between reversible and irreversible expansion and how we are able to differentiate between the two

Thanks!

[Jessica Helfond 2F]

A reversible reaction does more work than an irreversible reaction. This is because we change the volume infinitesimally, so we push against the force little by little to change the volume. This means a reversible reaction is slower, but more efficient. On the other hand, irreversible is fast but inefficient, and only pushes against a force once because the volume changes the entire amount at once. If a problem were to be under constant pressure, this means it's irreversible and you would use w=-pΔV. If the pressure is not constant, then it would be a reversible reaction and we would use w=-nRTln(v2/v1).

[Elizabeth Kim 4E]

A reversible reaction is more efficient because the volume changes very slowly and can easily be manipulated to reach equilibrium. However, an irreversible reaction moves very fast and uses large amounts, so it is harder to reach equilibrium easily, so therefore it is irreversible.