Reversible vs irreversible  [ENDORSED]


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Abbey Kerscher 3O
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Reversible vs irreversible

Postby Abbey Kerscher 3O » Fri Jan 20, 2017 1:10 pm

What does irreversible expansion mean?

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Joined: Fri Jan 08, 2016 3:00 am

Re: Reversible vs irreversible  [ENDORSED]

Postby Diana_OToole_1F » Sat Jan 21, 2017 7:51 pm

Pages 32-33 of the Course Reader say:

Systems are often approximated as reversible: calculate maximum work
wmax = wrev (>wirr)

All real processes are irreversible. Biochemical systems often use highly irreversible reactions to speed up the process. But less efficient (less useful work done) wrev>wirr

Reversible Pathway: Temperature (Constant), Volume increases, Pressure decreases
w = -nRT ln (V2/V1)
more work done

Irreversible Pathway: Temperature changes along pathway, Work done against constant external Pressure
w = -P delta V
less work done

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Re: Reversible vs irreversible

Postby BridgetJ_2J » Sat Jan 21, 2017 7:56 pm

Irreversible expansion refers to a process (or reaction) that occurs in large, finite steps that would make reversing it statistically improbable- meaning that the initial state of both the system and its surroundings cannot be restored once the final state has been reached. An example would be like if you were to spill a glass of milk onto to a table. The chance of the milk reversing and going back into the glass once it has been spilled (without human interference) is highly unlikely- making it an irreversible process.

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