Talk:Law of mass action

message: Shouldn't the equilibrium constant be equal to [C][D]/[A][B]?
From what I've read, they seem to be swapping products with reactants here.
: If you read the article more carefully then you will find that the same thing is written there. Loom91 08:59, 9 November 2006 (UTC)
thread_title:  Equilibrium constant 

message: This seems to be saying that the kinetic order of a reaction with respect to each reactant will always be whatever coefficient goes in font of it in the balanced equation. Is this generally regarded as being correct? Because it's perfectly plausible to have a reaction like A + B -> C that is second order with respect to the concentration of “A”.
: For a single-step/concerted reaction (the only type for which the Law of Mass Action is valid), the kinetic order of a reactant is indeed equal to its coefficient in the balanced (and correct) stoichiometric equation reduced to its lowest terms. Examples where this is not true all have a multi-step/non-concerted mechanism. Loom91 12:26, 23 January 2007 (UTC)
thread_title:  Kinetic order 

message: The content of this article is all wrong!!!
I am currently reading the original papers by Guldberg and Waage of 1867 and 1869 in Ostwald's Klassiker der Exacten,Wissenschaften, volume 104, so please leave this article alone until I have finished the revision. There are major discrepancies between what they wrote and what I thought they had written. Petergans 09:53, 20 June 2007 (UTC)
replies: text: May I remind you that no one owns Wikipedia articles. Please point out what parts of this article you consider wrong. Also notice that this article is not solely on the history of Mass Action, so it can not be based exclusively on what Guldberg and Waage had said in 1867 and 1869. Loom91 13:25, 21 June 2007 (UTC)

text: Your allegation is ridiculous. Good luck getting an admin to support your cause, which seems to be focused more towards intimidating your opponents by flaunting your credentials and asking admins to take action against them than towards conducting reasonable discussions on content. In your post, you didn't say a single word about the article. Loom91 12:58, 22 June 2007 (UTC)

text: You are abusing the  template. It should be used in moderation, definitely not when you are on a lunch break. Please refrain from using it unless you are actually editing at that moment. I agree with your rename proposal. Wikipedia is a collaborative system, please learn to respect other editors' contributions and build on them, rather than doing rewrites. Loom91 19:02, 23 June 2007 (UTC)
thread_title:  Revision 

message: There is a fundamental misconception at the heart of this version. The Law of Mass Action is not about kinetics, it is about equilibrium.  To find the values of the empirical constants a, b, a’, b’ and k+/k-, as in
:\frac{dx}{dt}=k(p-x)^a(q-x)^b
and 
:\left( \frac{dx}{dt}\right) '=k'(p'+x)^{a'}(q'+x)^{b'}
Guldberg and Waage observed reactions as a function of time in order to have sufficient data  to determine all the unknowns. Their objective was always to quantify “chemical affinity”, as is clearly indicated by the titles of their papers. 
This misconception was evident in the old versions before 14 May. Other fundamental errors in that version are the statements
*“proportional to its chemical activity”; must be proportional to concentration.
*“product of the effective concentrations”;  “effective” cannot be correct since reaction rates are always measured as a function of concentration.
These two errors arise from a faulty interpretation of the modern theory of equilibrium constants in terms of kinetics ideas and a misunderstanding of the term “active mass”.. The remainder of the original article was all about kinetics and is irrelevant to the central topic of equilibrium. There was nothing to build on here so a re-write was needed.
The edit by Loom91 on 24 June is not a clean-up, but a mess-up.
*The emphasis of the article was changed from equilibrium back to the misconceived emphasis on kinetics.
*The above mentioned errors were re-introduced
*The article now contains three statements of the law, all different 
*The lead-in, which gave the context has been deleted
*The reference to other meanings was deleted
*The expressions in “the law” are inconsistent with the earlier definition of affinity, since exponents are missing
*Forward and backward reaction rates are shown in terms of activity, not concentration
*The crucial issues of generalisation and stoichiometric coefficients have been deleted. These define the law of mass action as we know it today.
*A detailed discussion of kinetics is not needed as equilibrium constants are hardly ever determined by kinetics nowadays. 
*The references to biochemical issues are irrelevant here because they are concerned with the difference in kinetics inside and outside of a cell.
*There is no “modern” law of mass action. Equilibrium constants are now based thermodynamics and the theory of kinetics has evolved out of all recognition.  
*There are many minor faults such as unnecessary repetition and non sequiturs.
In an attempt to resolve the conflict I have separated the historical and contemporary  material. The historical section should not be edited for content (unless the editor has read the original papers) since it is based directly on Guldberg and Waage’s publications.
: Now I undestand the rationale behind your peculiar editing, it all stems from the fundamental misconception that the law of mass action is about equilibrium rather than kinetics. The law of mass action is a stement about rates of reactions (as can be verified from the countless textbooks available in the market), so it is firmly a law of kinetics. Equilibrium considerations are secondary. I stress again that this article is not (solely) about the historical development of the law as you seem to think. Merely writing from the outdated papers will not give a balanced article. The law of mass action is firmly about kinetics. The small errors you point out can be cleaned up without messing up the whole article. To discuss your points:
:*Your lead was perhaps the most atrocious section of the article. It seemed to start at the middle of a history textbook, completely lacking any context or summarisation of article. I suggest you review Wikipedia's community style guides to see what leads are supposed to be like.
:*The whole concentration/activity issue has been discussed in the article itself.
:*I do not see that stoichiometric coefficients have been deleted. They are very much present in the article.
:*I've no particular fondness for the biochemical section. Perhaps we should retain a line or two as an illustration and delete the rest.
: All the other points you raised are based on your strange idea that for some reason the law of mass action is about equilibrium. Unfortunately, your view is not supported by standard and reputable sources. May I suggest that you implement any proposed changes one part at at a time instead of starting anew every time. Loom91 08:16, 28 June 2007 (UTC)
replies: text: By the way, your description of me as a loose cannon is rather amusing ;-) If you look carefully at the diffs (as I do) then you will find that little of the actual content you added has been reverted. I've mostly reorganised, cleaned-up and added back sections you had deleted. Loom91 08:31, 28 June 2007 (UTC)
thread_title:  Second revision 

message: Shouldn't the equilibrium constant be equal to [C][D]/[A][B]?
From what I've read, they seem to be swapping products with reactants here.
: If you read the article more carefully then you will find that the same thing is written there. Loom91 08:59, 9 November 2006 (UTC)
thread_title:  Equilibrium constant 

message: This seems to be saying that the kinetic order of a reaction with respect to each reactant will always be whatever coefficient goes in font of it in the balanced equation. Is this generally regarded as being correct? Because it's perfectly plausible to have a reaction like A + B -> C that is second order with respect to the concentration of “A”.
: For a single-step/concerted reaction (the only type for which the Law of Mass Action is valid), the kinetic order of a reactant is indeed equal to its coefficient in the balanced (and correct) stoichiometric equation reduced to its lowest terms. Examples where this is not true all have a multi-step/non-concerted mechanism. Loom91 12:26, 23 January 2007 (UTC)
thread_title:  Kinetic order 

message: The content of this article is all wrong!!!
I am currently reading the original papers by Guldberg and Waage of 1867 and 1869 in Ostwald's Klassiker der Exacten,Wissenschaften, volume 104, so please leave this article alone until I have finished the revision. There are major discrepancies between what they wrote and what I thought they had written. Petergans 09:53, 20 June 2007 (UTC)
replies: text: May I remind you that no one owns Wikipedia articles. Please point out what parts of this article you consider wrong. Also notice that this article is not solely on the history of Mass Action, so it can not be based exclusively on what Guldberg and Waage had said in 1867 and 1869. Loom91 13:25, 21 June 2007 (UTC)

text: Your allegation is ridiculous. Good luck getting an admin to support your cause, which seems to be focused more towards intimidating your opponents by flaunting your credentials and asking admins to take action against them than towards conducting reasonable discussions on content. In your post, you didn't say a single word about the article. Loom91 12:58, 22 June 2007 (UTC)

text: You are abusing the  template. It should be used in moderation, definitely not when you are on a lunch break. Please refrain from using it unless you are actually editing at that moment. I agree with your rename proposal. Wikipedia is a collaborative system, please learn to respect other editors' contributions and build on them, rather than doing rewrites. Loom91 19:02, 23 June 2007 (UTC)
thread_title:  Revision 

message: I have re-written the article on elementary reactions and transferred some material there. This has allowed the last section to be presented in a more logical fashion. Petergans 10:38, 24 July 2007 (UTC)
thread_title:  The last part 

message: Petergans, what do you mean by duplicate derivation? Loom91 06:37, 27 July 2007 (UTC)
replies: text: What you had written is virtually identical with the derivation in the 1879 section, which I had modified to be explicit in terms of reaction rate. Incidentally, the meaning of the subscript f is not clear. Petergans 08:47, 27 July 2007 (UTC)
replies: text: They are not identical. The 1879 section uses affinity constants and active masses. Simply writing that the affinity constants are rate constants, without writing out what expression is beiing referred to, is confusing. Particularly since the contemporary view is a separate section and some readers may decide to read only that section, without reading the history. Loom91 17:47, 29 July 2007 (UTC)
thread_title:  What duplicate derivation? 

message: I think we should refer to mass action as a mathematical model.  It is rather a simplified version of the chemical master equation that was tractable and is good enough for some cases.  But now we are seeing many exceptions and I think it's better to take the more conservative route and refer to mass action as a model, not a law.  —Preceding unsigned comment added by Neffk (talk • contribs) 21:09, 25 August 2009 (UTC)
thread_title:  Law vs. Model 

message: The law of mass action is very important in semiconductor physics, and although I believe the maths to be exactly the same, the application is quite different. I've added a stub of a section for that, but if someone more knowledgeable than me could extend it, I think that'd be really helpful.  —Preceding unsigned comment added by 131.111.8.97 (talk) 14:36, 12 November 2009 (UTC)
thread_title:  Semiconductor Physics 

message: It is alleged that this law is inconsistent with the concept of water memory.--5.15.23.245 (talk) 23:30, 15 December 2013 (UTC)
thread_title:  Water memory 

message: Is this law about kinetics, as some recent edits try to imply? As I recall, this law is not about kinetics as one can see in the comtemporary view section. It has been indeed derived kinetically at its formulation by Guldberg and Waage. Then van′t Hoff rediscovered the kinetic rate equation needed in the derivation by GW.--188.27.144.144 (talk) 09:28, 17 December 2013 (UTC)
replies: text: The equivalent pages in french, deutch and spanish clearly state that this law is about thermodynamics. There seems to have been an edit war and the current version is very... confusing Lewisiscrazy (talk) 06:53, 25 January 2018 (UTC)
thread_title:  Kinetics 

message: The page, as it is currently written, should be renamed to "Historical Overview of the Law of Mass Action". It's really hard to read this page to get any useful intuition on the subject - a definition was lacking and any explanation was hidden in a lengthy discussion of the articles defining it, more than a hundred years ago. The page should be focused on modern use of the term. I added a definition, which I rephrased from the web (and cited), and I hopefully got it right. I would like someone to go over it and make their suggestion.
--Kwikwag (talk) 14:41, 3 September 2015 (UTC)
thread_title:  Serious need of definition 

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thread_title:  External links modified 

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thread_title:  External links modified 

message: I have a question concerning the two excerpts:
"The derivation from the reaction rate expressions is no longer considered to be valid." 
... and later on....
"In general many reactions occur with the formation of reactive intermediates, and/or through parallel reaction pathways. However, all reactions can be represented as a series of elementary reactions and, if the mechanism is known in detail, the rate equation for each individual step is given by the r_f  expression so that the overall rate equation can be derived from the individual steps. When this is done the equilibrium constant is obtained correctly from the rate equations for forward and backward reaction rates."
Isn't this a contradiction? So if I know all reactions, a derivation from the reaction rate expression IS Valid?
89.15.167.48 (talk) 10:42, 19 January 2018 (UTC)
thread_title:  reaction rate 

message: Can there be some kind of brief etymology section or at least an explanation of what the name of this article means? The name of this law doesn't make sense to me and I can't find any explanation for why it's called "mass action". There's a definition of something called "active mass" in the middle of the History section of the article (which probably would have been more helpful in the introduction), but then why isn't it just called Law of Active Masses? If this was just an arbitrary naming choice on the part of the people who wrote the original papers, then it would be nice if the article said that somewhere. thanks 64.33.129.250 (talk) 00:56, 2 February 2022 (UTC)
thread_title:  what does "mass action" mean?