w=-PdeltaV

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Jose Torres
Posts: 31
Joined: Fri Sep 28, 2018 12:22 am

w=-PdeltaV

Postby Jose Torres » Wed Feb 06, 2019 10:56 pm

For both work equations of w=-nRTln(V2/V1) and w=-PdeltaV, what are all the conditions in which we would use one over the other?

Amy Lefley 1J
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: w=-PdeltaV

Postby Amy Lefley 1J » Wed Feb 06, 2019 11:01 pm

Use the equation W=-PdeltaV for a sudden irreversible expansion when work is done against a constant external pressure and temperature changes - less work is done for this pathway.

Ue the other work equation for a reversible expansion, when temperature is constant, external pressure is not constant, and more work is done.

Nicholas Le 4H
Posts: 74
Joined: Fri Sep 28, 2018 12:24 am

Re: w=-PdeltaV

Postby Nicholas Le 4H » Fri Feb 08, 2019 9:06 am

The first equation would only be used for questions that deal with reversible expansion, while the second equation of w=-PdeltaV would only be used for irreversible expansion.

EllaBerry
Posts: 68
Joined: Fri Sep 28, 2018 12:29 am

Re: w=-PdeltaV

Postby EllaBerry » Fri Feb 08, 2019 8:59 pm

The first equation is used in the case of a reversible expansion, meanwhile the second equation is used in the case of an irreversible expansion.

Alexa Tabakian 1A
Posts: 38
Joined: Fri Sep 28, 2018 12:20 am

Re: w=-PdeltaV

Postby Alexa Tabakian 1A » Fri Feb 08, 2019 11:49 pm

The first one is for reversible expansion, and the second one is for irreversible expansion.

Lasya Gudipudi 1A
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

Re: w=-PdeltaV

Postby Lasya Gudipudi 1A » Sat Feb 09, 2019 12:57 am

The first one is used when the external pressure is not constant, which is reversible expansion, and the other equation is used when the external pressure is constant, which is irreversible expansion.

Niveda_B_3I
Posts: 60
Joined: Fri Sep 28, 2018 12:24 am

Re: w=-PdeltaV

Postby Niveda_B_3I » Sun Feb 10, 2019 4:46 pm

-PdeltaV would be used if your external pressure is constant, and with irreversible reactions.


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