Work done by Reversible vs. Irreversible Reactions


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Hailey Johnson
Posts: 31
Joined: Wed Nov 16, 2016 3:04 am

Work done by Reversible vs. Irreversible Reactions

Postby Hailey Johnson » Sun Jan 28, 2018 6:07 pm

Hi, I missed a few minutes of a lecture last week and missed Dr. Lavelle talking about this concept in detail. Can someone please explain to me why a reversible reaction does more work than an irreversible reaction.

Justin Chu 1G
Posts: 52
Joined: Thu Jul 13, 2017 3:00 am
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Re: Work done by Reversible vs. Irreversible Reactions

Postby Justin Chu 1G » Sun Jan 28, 2018 6:19 pm

Based on my understanding, a reversible reaction always does the max amount of work possible since it would have to be in equilibrium. Also, all real processes are irreversible and these irreversible reactions tend to be much faster but less efficient (do less work).

Katie Blann 1E
Posts: 29
Joined: Tue Nov 15, 2016 3:00 am

Re: Work done by Reversible vs. Irreversible Reactions

Postby Katie Blann 1E » Sun Jan 28, 2018 6:22 pm

A reversible process is slower so less of the energy is lost as heat. Where a irreversible process tends to generate more friction and more heat is lost to the surroundings.

Emma Li 2C
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Re: Work done by Reversible vs. Irreversible Reactions

Postby Emma Li 2C » Sun Jan 28, 2018 6:33 pm

A reversible process means that the system is at equilibrium, where the pressure of the surroundings and the system are equal. In expansion, a tiny decrease in the surrounding pressure results in a tiny push up by the system on the piston. If expansion continues to occur in very very small steps, we could use an integral to sum up an infinite number of steps, and this would give us the max work possible :)

Yixin Angela Wang 2H
Posts: 51
Joined: Thu Jul 27, 2017 3:00 am

Re: Work done by Reversible vs. Irreversible Reactions

Postby Yixin Angela Wang 2H » Sun Jan 28, 2018 11:30 pm

Dr. Lavelle gave the example of a piston weighed down by sand. The reversible reaction would occur if the weight was removed, grain by grain, slowly. This way, there wouldn't be energy lost as heat.


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