Reversibility and Entropy  [ENDORSED]

Moderators: Chem_Mod, Chem_Admin

Payton Kammerer 2B
Posts: 49
Joined: Tue May 01, 2018 3:00 am

Reversibility and Entropy

Postby Payton Kammerer 2B » Sun Feb 09, 2020 11:00 pm

In the lecture, Prof Lavelle said that since entropy is a state function, the reversibility of a reaction doesn't matter in calculating delta S. I am a little confused about this, since we also know that entropy increases with the number of possible states, and the components of reversible reaction have more possible states than an irreversible reaction, right? Is my misunderstanding in what a reversible reaction is, what a state function is, or what the effect of possible states on entropy is?

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

Re: Reversibility and Entropy  [ENDORSED]

Postby Chem_Mod » Mon Feb 10, 2020 10:22 am

A reversible pathway is different from state functions.

One can calculate the change in volume by knowing the initial and final volumes because volume is a state function.
One does not need to know if the volume change was along a reversible or irreversible pathway.

Entropy and volume are both state functions.

One can only calculate the work done if one knows the details of the pathway along which the change occurred, and the amount of work done is different for reversible or irreversible pathways.

Hopefully this clarifies what I said in class.

Chem_Mod
Posts: 18400
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 435 times

Re: Reversibility and Entropy

Postby Chem_Mod » Mon Feb 17, 2020 6:55 pm

Make sure to go over these in discussion sections and peer learning sessions.


Return to “Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)”

Who is online

Users browsing this forum: No registered users and 2 guests