Reversible Expansion


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Brandon Mo 4K
Posts: 70
Joined: Fri Sep 28, 2018 12:15 am

Reversible Expansion

Postby Brandon Mo 4K » Fri Feb 08, 2019 1:13 am

Could someone explain the derivation of work of reversible expansion? Also, what is the difference between reversible work and irreversible?

Jerome Mercado 2J
Posts: 60
Joined: Tue Nov 28, 2017 3:02 am

Re: Reversible Expansion

Postby Jerome Mercado 2J » Fri Feb 08, 2019 11:47 am

A reversible expansion has a pressure that is constantly changing therefore the derivation of volume (the area under the curve) is needed to show a changing pressure. That is why the integral goes from one volume to another and why work for a reversible expansion is

w=-nRTln(V2/V1)

while a irreversible reaction has constant external pressure thus work is just simply:

w = -PdeltaV

Aria Soeprono 2F
Posts: 64
Joined: Fri Sep 28, 2018 12:27 am

Re: Reversible Expansion

Postby Aria Soeprono 2F » Fri Feb 08, 2019 12:24 pm

This might be an obvious question, but will a problem always tell you explicitly if it is reversible or irreversible?

michelle
Posts: 62
Joined: Fri Sep 28, 2018 12:23 am

Re: Reversible Expansion

Postby michelle » Fri Feb 08, 2019 5:25 pm

For an irreversible system, work is done under constant pressures and energy is lost as heat. For a reversible system, each energy lost by doing work will come back to the system as heat, and it is more efficient.


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