en>Gilliam: Reverted edits by 182.70.111.236 (talk) to last version by SeoMac

2014-12-02T06:35:34Z

Reverted edits by 182.70.111.236 (talk) to last version by SeoMac

en>Excirial: Reverted edits by Davidking018 (talk) (HG 3)

2014-01-27T20:00:18Z

Reverted edits by Davidking018 (talk) (HG 3)

← Older revision		Revision as of 22:00, 27 January 2014
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	~~The author is recognized by~~ the ~~name~~ of ~~Numbers Lint~~. ~~North Dakota is our birth place~~. ~~Hiring~~ has ~~been my occupation for some time but I~~'~~ve already utilized~~ for ~~another 1~~. ~~What I love doing is to collect badges but I~~'~~ve been taking~~ on ~~new things lately~~.<br><br>~~my website; std testing~~ at ~~home~~ - [http://~~Richlinked~~.~~com~~/~~index~~.~~php?do~~=/~~profile-32092~~/~~info~~/ ~~this site~~] -		In [[chemical kinetics]] a '''reaction rate constant''', ''k'' or <math>\lambda</math>, quantifies the rate of a [[chemical reaction]].<ref>http://www.chem.arizona.edu/~salzmanr/480a/480ants/chemkine.html</ref>

			For a [[chemical reaction]] where substance A and B are reacting to produce C, the [[reaction rate]] has the form:

			:<big> Reaction: A + B → C </big>

			:<math>r = k(T)[A]^{m}[B]^{n}</math>

			''k''(''T'') is the reaction rate constant that depends on temperature.

			[A] is the [[concentration]] of substance A in [[mole (unit)\|moles]] per volume of solution assuming the reaction is taking place throughout the volume of the solution (for a reaction taking place at a boundary it would denote something like moles of A per area).

			The exponents ''m'' and ''n'' are called partial [[order of reaction\|orders]] and depend on the [[reaction mechanism]]. They can be determined experimentally.

			A single-step reaction can also be written as

			:<math>r = Ae^\frac{-E_a}{RT}[A]^m[B]^n,</math>

			where ''E<sub>a</sub>'' is the [[activation energy]], and ''R'' is the [[gas constant]]. Since at [[temperature]] ''T'' the molecules have energies according to a [[Boltzmann distribution]], one can expect the proportion of collisions with energy greater than ''E<sub>a</sub>'' to vary with ''e''<sup>−''E<sub>a</sub>''/''RT''</sup>. ''A'' is the [[pre-exponential factor]], or frequency factor.

			The [[Arrhenius equation]] gives the quantitative basis of the relationship between the [[activation energy]] and the [[reaction rate]] at which a reaction proceeds.
			== Units ==
			The units of the rate constant depend on the global [[order of reaction]]:<ref>{{cite web\|last=Blauch\|first=David\|title=Differential Rate Laws\|url=http://www.chm.davidson.edu/vce/kinetics/differentialratelaws.html\|work=Chemical Kinetics}}</ref>
			If concentration is measured in [[Molar concentration#Units\|units]] of mol·L<sup>−1</sup> (sometimes abbreviated as M), then
			* For order (''m'' + ''n''), the rate coefficient has units of mol<sup>1−(''m''+''n'')</sup>·L<sup>(''m''+''n'')−1</sup>·s<sup>−1</sup>
			* For order zero, the rate coefficient has units of mol·L<sup>−1</sup>·s<sup>−1</sup> (or M·s<sup>−1</sup>)
			* For order one, the rate coefficient has units of s<sup>−1</sup>
			* For order two, the rate coefficient has units of L·mol<sup>−1</sup>·s<sup>−1</sup> (or M<sup>−1</sup>·s<sup>−1</sup>)
			* And for order three, the rate coefficient has units of L<sup>2</sup>·mol<sup>−2</sup>·s<sup>−1</sup> (or M<sup>−2</sup>·s<sup>−1</sup>)

			==Plasma and gases==
			Calculation of rate constants of the processes of generation and relaxation of electronically and vibrationally excited particles are of significant importance. It is used, for example, in the computer simulation of processes in [[plasma chemistry]] or [[microelectronics]]. First-principle based models should be used for such calculation. It can be done with the help of [[computer simulation]] software.

			==See also==
			*[[Reaction rate]]
			*[[Equilibrium constant]]

			==References==
			{{Reflist}}

			[[Category:Chemical kinetics]]

			{{chem-stub}}

en>Glrx: rvt last 2; earlier illustration is less like a black box; shape relates to discussion; new fig does not relate

2012-08-29T18:21:36Z

rvt last 2; earlier illustration is less like a black box; shape relates to discussion; new fig does not relate

New page

The author is recognized by the name of Numbers Lint. North Dakota is our birth place. Hiring has been my occupation for some time but I've already utilized for another 1. What I love doing is to collect badges but I've been taking on new things lately.<br><br>my website; std testing at home - [http://Richlinked.com/index.php?do=/profile-32092/info/ this site] -

Mass flow meter - Revision history

en>Gilliam: Reverted edits by 182.70.111.236 (talk) to last version by SeoMac

en>Excirial: Reverted edits by Davidking018 (talk) (HG 3)

en>Glrx: rvt last 2; earlier illustration is less like a black box; shape relates to discussion; new fig does not relate