Talk:Chemical potential
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[edit] Random comments
1) Chemical Potential is a noun, it should not be described as a verb, such as "change".
2) Constituent: an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system
A particle is added to a group of particles. The energy required defines the chemical potential. I ommited the word "constituent particle" because the additional particle need not be "one of the individual [particles] of which the [group of particles]" is added to. A chemical potential is still defined if I take a particle that is not a member of the group of particles and add it to the group of particles.
3) Point 1) above is not right. Change can be a noun as well as a verb. E.g., if I change (v.) x to x+1, then the change (n.) in x is 1.
4) The fundamental concept of the chemical potential (1st sentence of the article) as being the change in energy on adding a particle, is often (in many books and papers) taken literally to mean a finite difference F(N+1)-F(N), where N=number of particles and F is either the internal energy or the Helmholtz free energy (the difference is taken at constant entropy and volume in the former case, at constant temperature and volume for the latter). That this can be essentially incorrect for finite systems (even for some very large finite systems) has been discussed recently (see The Chemical Potential, by T. A. Kaplan, J. Stat. Phys. 122, 1237 (2006)).--Tomkaplan 19:16, 3 January 2007 (UTC)
5) Appreciation of unity in physics where it exists is clearly desirable. Making a distinction between `thermodynamic chemical potential' and `electronic chemical potential' seems to introduce a fundamental distinction where it, in fact, does not exist: the electronic version introduced in the main page of this subject is actually the zero-temperature limit of the thermodynamic chemical potential. For this see J. P. Perdew in Density-functional methods in Physics}, edited by R. M. Dreizler and J. da Providencia, Plenum, New York, 1985, and T. A. Kaplan, J. Stat. Phys. 122,1237 (2006). Thus the distinction, as presented in the fundamental definitions section of the article on the chemical potential, is highly undesirable.--Tomkaplan 19:16, 3 January 2007 (UTC)
[edit] History?
There is no history on this term, or its usage. If I recall correctly, it was Gibbs who first used the term and its mathematical definition.
- Yes, I fixed this.--Sadi Carnot 15:12, 25 July 2006 (UTC)
[edit] Other Contexts
Chemical potential plays a huge role in the theories of chemical equilibria. But it also plays a role in chemical species diffusion, bose-einstein condensation, etc.. There's a lot of room to expand.
[edit] Should this article be split?
I believe this article should eventually be split into 2 articles and then have a disambiguation page. Theoretical chemists use the term "chemical potential" to refer to the electronic chemical potential. All other chemists use the term "chemical potential" to refer to the thermodynamic chemical potential. It seems totally obvious to me, but this confuses nearly all chemists (because the electronic chemical potential is rarely discussed in undergraduate course work - and even in graduate course work).
For the time being, what is written might suffice; however, if/when more content is added to describe the electronic chemical potential more accurately and completely (including the principle of chemical potential equalization arising from density functional theory - here refering to the electronic chemical potential), the amount of content and the mixing of the terminology on the same page may prove far too confusing. --anon
- I broke it up into sections and added a description of the electronic chemical potential. It seems to work fine, in my opinion. I don't think splitting it up into several pages is necessary. I need to include some references, but I am awfully tired right now. --anon 06:00, 2 December 2005 (UTC)
[edit] Relativistic chemical potential?
I think that the section titled relativistic chemical potential should either be clarified by an expert or removed. It is totally unclear to me what the relativistic chemical potential is. It is stated as being related to symmetries and charges, but some sort of definition (preferably an equation) seems necessary (I mean, there's all sorts of things related to symmetries and charges, so it is quite a vague description).
I don't do any relativistic-stuff, but I am fairly well-versed in atomic physics, in general, and if it's not clear to me I highly doubt it's clear to anyone other than the original author. I'm going let it sit for a day-or-so, and then just remove it unless there is any discussion or changes. DrF 03:43, 24 May 2006 (UTC)
- Added Expert request tag. I'll let this section sit a little while longer before I delete it. DrF 04:20, 26 May 2006 (UTC)
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- This reads about right I clean it a bit and add a ref link for those who want to read more.--Sadi Carnot 15:12, 25 July 2006 (UTC)
