Converting to q rev


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Marsenne Cabral 1A
Posts: 59
Joined: Fri Sep 28, 2018 12:19 am

Converting to q rev

Postby Marsenne Cabral 1A » Sat Feb 16, 2019 9:37 pm

Even if the reaction you have is irreversible, do you still use change in entropy= qrev/T?

Yousif Jafar 1G
Posts: 59
Joined: Thu May 10, 2018 3:00 am

Re: Converting to q rev

Postby Yousif Jafar 1G » Sat Feb 16, 2019 10:38 pm

unless it is isothermal and irreversible, you use the other formulas were change in entropy is =nRlnT2/T1

Yvonne Du
Posts: 64
Joined: Fri Sep 28, 2018 12:23 am

Re: Converting to q rev

Postby Yvonne Du » Sat Feb 16, 2019 11:35 pm

Yes, qrev/Delta T would be the formula for irreversible reaction.

ryanhon2H
Posts: 60
Joined: Fri Sep 28, 2018 12:28 am

Re: Converting to q rev

Postby ryanhon2H » Sun Feb 17, 2019 2:06 am

Because entropy is a state function, the change will be the same regardless of whether the reaction is reversible or not, since it is not path dependent, so you can use qrev/T, as long as the reaction is isothermal. If it is isobaric (constant pressure), isochoric (constant volume), etc you would have to use a different equation.

105169446
Posts: 32
Joined: Fri Sep 28, 2018 12:16 am

Re: Converting to q rev

Postby 105169446 » Sun Feb 17, 2019 10:32 pm

When the change in entropy is reversible, you can also use delta S = nrln(V2/V1) or delta S = nCln(P1/P2) because pressure is inversely related to volume.


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