Talk:Chemical kinetics

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Comment[edit]

I suggest that chemical kinetics is limited to give a general overview and leave details to other articles, for instance reaction rate, reaction mechanism already have their own articles. chemical kinetics is a very broad topic simply inpossible to discuss it all in a single article (comment by V8rick)

I agree that chemical kinetics is the best article to serve as a general overview. Right now there are several small articles which deal with aspects of chemical kinetics. I hope this is the complete list: rate equation, Reaction rate, reaction rate constant, Reaction mechanism, Arrhenius equation, Frequency factor (chemistry), Activation energy, Order (chemistry), Reactivity, Reactivity series, Transition state, Activated complex, Rate-determining_step, Baeyer strain theory, Dynamic stereochemistry, Kinetic_isotope_effect, Catalyst, Homogeneous catalysis, Heterogeneous catalysis, Autocatalysis, Autocatalytic set,Rate_of_enzyme_mediated_reactions, Michaelis-Menten kinetics, Enzyme, Femtochemistry. There is a lot of overlap in these articles. I therefore have a tendency to merge several of them.
Despite the great number of articles there is not a lot of material on chemical kinetics in WP. Eyrings transition state theory is completely missing. There is no information how kinetics can be measured. But given the current small size of chemical kinetics there is still ample room to add these aspects.
I guess that the discussion about the exact forms of the rate equations in chemical kinetics could be moved to rate equation but I don't see any pressing need because of the small current size of chemical kinetics. Currently, I think that we can safely merge rate equation into chemical kinetics. We are nowhere near to producing a large article on the subject and if the article turns out to be very large we can always split it up later. But I don't feel strongly about it either way.

I wanna add something here. Actually I expect to read more about the consequences between temperature, kinetics energy, volumes, thermal energy, the movement of the atom and so on because i'm quite confuse about how actually the process goes when an object is heated and then it gets broken.

I do believe that reaction rate constant should be merged into rate equation, it is hardly more than a definition and I don't see how much more can be said about it. Similarly, I think that Activation energy and Arrhenius equation can be merged, one does not mean a lot without the other. I am less certain about merging Frequency factor (chemistry) into Arrhenius equation. It could be expanded to discuss collision theory results. Jan van Male 22:16, 31 Mar 2005 (UTC)

I believe that all the equations included in the article are workable, but I would appreciate it if someone could clean them up and make them look for uniform. Thanks.

--Michael 00:21, Mar 20, 2005 (UTC)

from PNA/Chemistry[edit]

  • Chemical kinetics - talks a bit confusingly about the kinetics of a particular type of reaction. No information at all about the field itself, i.e. history. --Smack (talk) 19:47, 11 Jan 2005 (UTC)
In the past year, this article has improved significantly. I vote to remove it from this list. EagleFalconn 06:14, 7 January 2006 (UTC)

new setup[edit]

moved the paragraph on reaction mechanism to reaction mechanism article, exactly add the content that was missing there thus far. Articles on reaction rate and rate law now clearly separated. proposal for this page: keep it general with history of, people in etc. All the different rate laws steady state, reversible first ordere, broken order reactions, pseudo first order (there exist dozens) to rate law article. experimental techniques to reaction rate article.

law of mass action[edit]

The statement on the law of mass action is wrong. The law of mass action relates the equilibrium constant to the concentrations / activities of the reactanting substances, and cannot predict the rate of a reaction.

Moreover, in most reactions there is no direct proportionality between the amount of a reactant and the speed of the reaction.

This article only makes a reference to the larger article called Law of mass action, just to put the chemical kinetics article in a historical context. If you want to challenge the statements made in the law of mass action article it would be more productive to make them there. V8rik 18:25, 28 December 2005 (UTC)

references[edit]

For mathematical derivation of the law of mass action, please visit www.geocities.com/simondex.


...pfft.... geocities huh? Try to find a credible site instead of personal user made pages. No offence. for example, wikipedia is not credible technically, but citing professionals, organizations, or governmental sites, helps it become more credible. • Storkian • 22:35, 28 September 2007 (UTC)

Gibb's free energy[edit]

There is an incorrect statement in the article: "In general terms, the standard enthalpy change of reaction determines if a chemical reaction will take place". What determines the spontainety of a reaction, that is, if it will happen, is not the standard enthalpy of the reaction but the Gibb's free energy. While the standard enthalpy of the reaction does play an important role in the expression for the free energy, the entropic term must not be neglected since it is actually the driving force for many reactions (for example, making a solution between water and potassium nitrate) that are actually endothermic and yet, exergonic.

Merge Reaction rate into Chemical Kinetics[edit]

While Chemical kinetics is a broad topic, fundamental information should be included such as: reaction rates, reaction mechanisms and catalysts. Very specific information can be given on articles that relate to Chemical Kinetics in their respective separate pages, but rate reactions are crucial to understanding kinetics. As such, information is duplicated in many parts by both articles, with the Reaction rate article listing more factors and synopses - including formula examples - and the Chemical kinetics article listing less factors but providing a more thorough explanation for why the factors influence reaction rates. Physical Chemist 20:10, 19 July 2006 (UTC)

Disagree, the chemical kinetics page should present a general overview of the subject without going into too much detail and avoiding formula's This is how I would like to see the page (one of the old versions):
Chemical kinetics
but over time the page tend to suck in all the content from the other pages, gets too long and too detailed. This is the information age: do not expect people to read more than 500 words on a single topic. My suggestion: keep reaction rate but scrap Factors influencing rate of reaction and move example. The main point is that you can always determine experimentally a reaction rate but you cannot always derive a sensible rate equation. V8rik 19:41, 20 July 2006 (UTC)
I would agree the Chemical kinetics article either needs to be a brief summary of all the basic topics with redirects, or almost complete redirects such as the version you linked to above. After looking at that version, I would suggest a move toward the latter, as the article in its current form does very little to address the needs of the former. If others agree that a move back toward a previous version would be appropriate I would welcome the input. Physical Chemist 16:59, 28 July 2006 (UTC)
Disagree. I just read through the article and it seems fine and informative the way it is. A person can best digest information when its comes in reasonably sizable chunks.--Sadi Carnot 14:36, 19 August 2006 (UTC)

That picture...[edit]

... is not good. Atoms or molecules do not have trails after them, nor do they have collision blobs. Olin 00:19, 26 January 2007 (UTC)

Chemical Kinetic Software[edit]

I think we should add links to free chemical kinetic software such as:IBM's CKS, KINTECUS, Dynafit and others. Maybe have it under a sub-page: Chemical Kinetics Software?

  • Its not really a useful thing to link, nor are the websites cited in the article.--RogueNinja 15:26, 18 March 2007 (UTC)

Most realistic chemical kinetics systems can only be conceptualized, created, solved, optimized and regressed by appropriate software that is also accurate and fast. The main chemical kinetic wiki article is quite misleading as most chemists, do NOT try to solve such systems by hand or even by utilizing mathematical software (like Mathcad).

But they tend to understand the math. That's why they don't trip over their socks when they start programming the software. 178.38.83.46 (talk) 19:55, 8 March 2015 (UTC)

General comment[edit]

With respect to all previous comments (above), there still are many things in this article, and the one on thermodynamic free energy, that need expert attention. I changed some, but I don't have the time to address them all. Help! - Astrochemist (talk) 04:14, 26 November 2007 (UTC)

in general;the rate of chemical reaction deal on the factor that affect the rate of chemical reaction and the speed of a chemical reaction.N:B Rate of a chemical reaction is direct proportion to the concentration of the reacting particle(reactant). —Preceding unsigned comment added by 81.199.178.42 (talk) 07:16, 5 April 2008 (UTC)

Kinetics influenced by stirring[edit]

Currently under catalysts the article says "Agitating or mixing a solution will also accelerate the rate of a chemical reaction, as this gives the particles greater kinetic energy, increasing the number of collisions between reactants and, therefore, the possibility of successful collisions."

I'm pretty sure that is a load of rubbish. Roughly speaking you can get the speed of a molecule from 1/2mv^2 = kbt. At room temperature for typical molecules you are talking about hundreds of m/s. So you won't make any real difference to the kinetic energy by stirring unless you are somehow stirring the molecules into each other at many m/s! To look at it another way, you don't increase the temperature of a solution much by stirring it.

Stirring helps because it ensures the reactants are mixed and your temperature is constant. Pretty sure that is it.

I'll remove unless there are objections.131.111.116.31 (talk) 17:19, 24 November 2014 (UTC)

I agree. Increase in K.E. would influence the thermodynamics of the reaction through an increase in temperature. But do shaken and stirred things become warmer? Only slightly, if you do it by hand. 178.38.83.46 (talk) 19:58, 8 March 2015 (UTC)