Naming Question  [ENDORSED]


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K Stefanescu 2I
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Joined: Fri Sep 29, 2017 7:04 am

Naming Question

Postby K Stefanescu 2I » Mon Feb 05, 2018 7:48 am

Why is reversible expansion called “reversible”?

Nina Gautam 1K
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Re: Naming Question

Postby Nina Gautam 1K » Mon Feb 05, 2018 8:40 am

We call it reversible because we are thinking about it as occurring in many small steps (infinitesimally small steps) rather than all at once, which gives us a more accurate work value. Because we are thinking about it in small steps as opposed to all at once, it can hypothetically occur in the opposite direction as well.

Clarisse Wikstrom 1H
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Re: Naming Question

Postby Clarisse Wikstrom 1H » Mon Feb 05, 2018 8:47 am

Can think of a reversible reaction as being at equilibrium?

Sohini Halder 1G
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Re: Naming Question

Postby Sohini Halder 1G » Mon Feb 05, 2018 9:57 am

The system starts at equilibrium (think Dr. Lavelle's example where both pressures are 1 atm) but an infinitesimally small change happens which starts the reversible process.

Lily Guo 1D
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Re: Naming Question

Postby Lily Guo 1D » Mon Feb 05, 2018 9:57 am

Reversible expansion is expansion that occurs as a result of infinitesimally small steps that can push the expansion either forward or backwards with the smallest of changes. This results in a maximum of work being done. In contrast, irreversible expansion is expansion that occurs as result of finite steps, and even if you were to "reverse" the step that resulted in expansion, work wouldn't be entirely conserved. The work done is less than maximum.

Chem_Mod
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Re: Naming Question  [ENDORSED]

Postby Chem_Mod » Mon Feb 05, 2018 2:34 pm

Slight elaboration, you can think of reversible processes being at equilibrium. With a reversible expansion, the external pressure is kept essentially equal to the internal pressure and is only very slowly changed so that both the inside and the outside are constantly in equilibrium. This is of course impossible in real life, but possible in theoretical representations.


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