Talk:Helmholtz free energy

message: :Does this article need to be marked as a stub? It seems at least somewhat comprehensive. If things are missing, how about the attention-tag? O. Prytz 21:54, 22 November 2005 (UTC)
replies: text: I think the stub tag can be removed. I will do it and see what happens. PAR 22:32, 22 November 2005 (UTC)
thread_title: Comment

message: The page urgently needs to have the word 'free' eliminated to comply with IUPAC recommendations.
Ref. http://goldbook.iupac.org/goldbook/H02772.html
Need to set up new page and convert this one into a REDIRECT. DIV, 2006-05-31 (Melbourne)
:The discussion was moved to Talk:Gibbs free energy, and can now be found in Talk:Gibbs free energy/Archive1.  
:Outcome after extensive discussion was strong consensus for No change -- continue with the title as Helmholtz free energy.
:Further points should be raised at Talk:Gibbs free energy.
:Jheald 11:25, 6 March 2007 (UTC)
thread_title: IUPAC compliance

message: If we wish to describe phenomena like chemical reactions, then the best we can do is to consider suitably chosen initial and final states in which the system is in (metastable) thermal equilibrium.
This sentence is necessary otherwise people may ask why we don't just use the expression of the Helmholtz energy in infinitessimal form and  then you get the paradox discussed in the previous section on this talk page. Note that that was exactly what was wrong with the version of this article of a few months ago with this article. Count Iblis (talk) 13:41, 1 September 2008 (UTC)
thread_title:  The best we can do is to consider suitably chosen initial and final states in which the system is in (metastable) thermal equilibrium. 

message: See . The tags should remain until this is clarified. Headbomb {ταλκκοντριβς – WP Physics} 01:28, 22 February 2010 (UTC)
replies: text: Are you crazy? Count Iblis (talk) 01:30, 22 February 2010 (UTC)
thread_title:  NPOV/Accuracy 

message: The article lacks consistency of variable formatting.  All variables should be italic.  Subscript labels that are not variables themselves should be roman.  This is generally adhered to in the display equations, but not throughout the body text. 
See IUPAC / SI / ISO guidelines on Use of Italic and Roman Fonts for Symbols in Scientific Text and Value and numerical value of a quantity, and the use of quantity calculus and ISO 31-0 Typographic conventions.  
—DIV (138.194.12.32 (talk) 09:30, 12 April 2010 (UTC)
thread_title:  Formatting 

message: Some people reading your article are new at thermodynamics (such as yours truly).
Would it help to clarify the difference between Helmholtz Free Energy and Gibb's Free Energy as follows?
H = U + PV
A = U - TS
G = H - TS
TS = U - A
TS = H - G
U - A = H - G
U - A = U + PV - G
A = G - PV
A < G
Or maybe it is easier to say
H = U + PV, so U < H by the amount PV
A = U - TS
G = H - TS
so A < G by the same amount that U < H, i.e., by the amount PV
Perhaps I am all wrong. These equations are all new to me. P times V is always positive, right? Or perhaps the article already contains this information -- maybe I missed it when I was reading the article.  
— Preceding unsigned comment added by Marvin W. Hile (talk • contribs) 15:10, 26 October 2012 (UTC)
replies: text: No, this misses an essential part of the discussion - which potentials go with which set independent variables ... which is the major talking point of the potentials. This is better captured, not by noting the algebraic relations, by the differential relations: dU = T dS - P dV, dA = -S dT - P dV, dG = -S dT + V dP and dH = T dS + V dP; and then noting how this generalizes with the inclusion of number and chemical potential, and with more or other canonical (intensive, extensive) pairs of variables (X, x) in place of or in addition to (-P, V). You could then note, afterwards, that A = U - ST (or, more properly: A(T,V) = U(S(T,V),V) - S(T,V) T, when S can be expressed in terms of T and V), G = U - ST + PV and H = U + VP (with similar qualifications about their respective functional dependencies), which can almost be read off directly from the differential relations.  — Preceding unsigned comment added by 2603:6000:AA4D:C5B8:0:3361:EAF8:97B7 (talk) 06:13, 5 April 2022 (UTC)
thread_title:  Helmholtz versus Gibbs 

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thread_title:  External links modified 

message: The derivation in Helmholtz_free_energy#Relation_to_the_canonical_partition_function works the same without introducing, then cancelling the variable X and the change Xdx ? CyreJ (talk) 08:35, 20 August 2020 (UTC)
thread_title:  Why Xdx?