+ instead of - for Maxwell Relation?

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    Maxwell Relation
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Homework Help Overview

The discussion revolves around the interpretation of Maxwell relations in thermodynamics, specifically questioning the sign convention used in a derived equation related to internal energy and work.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the correctness of a sign in a thermodynamic relation, with one participant attempting to clarify their understanding by re-deriving the relation and identifying a potential error in their previous work. Others raise concerns about the implications of different definitions of heat and work on the signs used in equations.

Discussion Status

The discussion is ongoing, with participants actively questioning the assumptions behind the sign conventions and providing corrections to links for reference materials. There is no explicit consensus yet, but some productive dialogue is occurring regarding the definitions of terms involved.

Contextual Notes

One participant notes a 404 error when attempting to access the original lecture notes, which may hinder the discussion. Additionally, the variability in definitions of dQ and dW is highlighted as a source of confusion in the context of the First Law of Thermodynamics.

pivoxa15
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In the lecture notes

http://webraft.its.unimelb.edu.au/64...n/lecture3.pdf

on the very last page, should the second realisation relation have -(dU/dp) instead of the + (dU/dp)?
 
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You need to fix the link. I get a 404 error.
 
Here is the site. Click on lecture 3 go to the last page

http://webraft.its.unimelb.edu.au/640322/pub/notes/common.html

I fixed up the error I think it is on this page and have edited my OP accordingly.
 
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I have derived it again and realized that I used the wrong dQ. It should have been dQ=dU-dW whereas I used dQ=dU+dW.
 
First Law applications can be an enormous pain in the ass - some people sometimes define dQ and dW as either done ON the system or done BY the system quite arbitrarily - which of course changes their sign.
 

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