Reversible vs. Irreversible Reactions

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Reversible vs. Irreversible Reactions

Postby rachelmackenzie3H » Sun Jan 15, 2017 1:43 pm

Can anyone give a good explanation as to why work done in a reversible reaction is always more than the work done in an irreversible reaction?

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Re: Reversible vs. Irreversible Reactions

Postby Chem_Mod » Sun Jan 15, 2017 6:46 pm

Reversible processes are by definition ideal processes which achieve 100% efficiency and waste zero energy. 100% efficiency means maximum work performed. In real life, nothing is like this and some energy is always lost meaning the work is less.

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Re: Reversible vs. Irreversible Reactions

Postby 704647747 » Tue Jan 17, 2017 9:45 am

Practically, I also try to think of the concept in this way:

Reversible process: If there is a syringe and you block the open tip of the syringe (so the air is trapped) and try to push in the plunger, then the force will induce a small change, but when you let it go, it'll rise back (be reversed).

Irreversible process: If you don't block the open tip of the syringe and push in the plunger, the same amount of force will induce a grater change, and when you let it go, the plunger will not rise back (irreversible). Here, the system and the surrounding will not be in an equilibrium when the pressure is released, either.

When you try it, you will see that the work (force * displacement) required to induce the "change" in the plunger in a reversible process will be greater than that required to induce the change in an irreversible process-

- is what I try to think of, but someone please correct me if I'm wrong, since I also am not 100% sure and would like to know if I am wrong as soon as possible.

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