Talk:Le Chatelier's principle

message: Response reactions is a new article which seems to be something on this topic but I don't know what it's on about... Can anyone help? Rd232 talk 13:48, 22 September 2009 (UTC)
thread_title:  Response reactions 

message: Why does this article on chemistry have a section on economy? While it may well be true, it has nothing to do with Le Chatelier, or chemical equilibrium. Would it not be better to move this out to a separate page, or refer to it in the "See also" links?  —Preceding unsigned comment added by Furrfu (talk • contribs) 12:58, 9 January 2010 (UTC)
thread_title: Economy?

message: I find the section entitled "Status as a Physical Law" to be misleading. The problem seems to be these sentences. I made some changes regarding (a).
(a) Le Chatelier's principle also states that when there is an external constraint on a system, a behavioural shift in the system occurs so as to annul the effect of that change.
(b) Where a shock initially induces positive feedback (such as thermal runaway), the new equilibrium can be far from the old one, and can take a long time to reach. In some dynamic systems, the end-state cannot be determined from the shock.
(c)  The principle ... applies, in general, to thermodynamically closed and isolated systems in nature, since the second law of thermodynamics ensures that the disequilibrium caused by an instantaneous shock must have a finite half-life.[1]
Le Chatelier's principle applies to chemical reactions that start in equilibrium, and adjust to a new equilibrium in an orderly way (not too far from linear) after a change in the amount of one participant. If the change is small enough, the adjustment will lie within the linear regime. If the change is somewhat larger -- and this can be quite large in many systems, for example, chemical solutions with not too many participants and monotone power-law type relations of quantities -- the adjustment will at least share the direction of the adjustment in the linear regime. In both cases, Le Chatelier's principle states that the system adjust so as to partially cancel the change in the amount of the externally changed participant. 
Several remarks:
(1) The shift does not annul the change, it only opposes it (partially annuls it). I would suggest removing sentence (a) -- in any case it mostly repeats the preceding sentence in the main text. In fact I did this.
(2) If the change (the "shock") is large enough, then we are way out of the linear regime, and naturally all bets are off -- thermal runaway being a good example. At this point, Le Chatelier's principle stops applying. Perhaps this should be said directly. As the text stands, I find the two sentences in (b) to be true, but distracting (a red herring), because no conclusion is drawn from them -- the correct conclusion being that we are out of bounds for Le Chatelier. And what does chaos have to do with it? Sure Le Chatelier's principle does not apply then!
(3) In any case, Le Chatelier's principle only says that the externally changed participant goes part of the way back to its old value. The other participant actually depart from their old values -- in fact, they absorb part of the change. So Le Chatelier's principle does not restore or return to the old equilibrium, but finds a new one (more or less nearby), with different numbers. "Opposition" only applies to the quantity of the externally changed participant. This means that (c) is misleading or wrong. In fact, it is seems to be generalizing the principle too much.
I made changes for (1), but I have trouble understanding the intent of the rest of the paragraph. It seems to me to be motivated by overarching philosophical drives that conflate together different kinds of dynamical phenomena to form overbroad principles. So I hesitate to make changes. 
84.226.178.205 (talk) 12:10, 19 October 2014 (UTC)
thread_title:  Too far afield 

message: I'm concerned about this article. On the one hand, it does have 13 references, but there are significant statements of fact that are not supported by a reference. The section on chemistry is over 1400 words with a single reference.
My chemistry knowledge is too weak to be a meaningful contributor to the science, but if someone's interested in working on this and has subject matter expertise, I will be happy to help. S Philbrick(Talk) 16:11, 16 July 2022 (UTC)
thread_title:  Citations needed 

message: Le Chatelier's principle belongs to thermodynamics, which is a branch of physics. It is a mistake to classify as belonging to physiology. Perhaps a forgivable mistake, but still a mistake. Because the wording is loose and qualitative, people try to appropriate it to areas beyond thermodynamics, but they are mistaken to do so. So the article's classification needs to be corrected.Chjoaygame (talk) 17:22, 9 February 2024 (UTC)
thread_title: Le Chatelier's principle is a special version of the second law