Kinetic fractionation


Kinetic fractionation

Kinetic fractionation is a process that separates stable isotopes from each other by their mass during unidirectional processes.

One naturally occurring example of kinetic fractionation is the evaporation of seawater to form clouds. In this instance, isotopically lighter water molecules (i.e., those with 16O) will evaporate slightly more easily than will the isotopically heavier water molecules with 18O.

During the course of this process the oxygen isotopes are fractionated: the clouds become enriched with 16O, the seawater becomes enriched in 18O. Thus, rainwater is observed to be isotopically lighter than seawater.

ee also

* equilibrium fractionation
* mass-independent fractionation


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Kinetic isotope effect — The kinetic isotope effect (KIE) is the ratio of reaction rates of two different isotopically labeled molecules in a chemical reaction. It is also called isotope fractionation, although this term is somewhat broader in meaning. A KIE involving… …   Wikipedia

  • Equilibrium fractionation — Equilibrium isotope fractionation is the partial separation of isotopes between two or more substances in chemical equilibrium. Equilibrium fractionation is strongest at low temperatures, and (along with kinetic isotope effects) forms the basis… …   Wikipedia

  • Mass-independent fractionation — Mass independent (isotope) fractionation refers to any chemical or physical process that acts to separate isotopes, where the amount of separation does not scale in proportion with the difference in the masses of the isotopes. Most isotopic… …   Wikipedia

  • Isotope fractionation — There are three types of isotope fractionation: * equilibrium fractionation * kinetic fractionation * mass independent fractionation …   Wikipedia

  • isotopic fractionation — ▪ chemistry       enrichment of one isotope relative to another in a chemical or physical process. Two isotopes of an element are different in weight but not in gross chemical properties, which are determined by the number of electrons. However,… …   Universalium

  • Stable isotope — Graph of isotopes/nuclides by type of decay. Orange and blue nuclides are unstable, with the black squares between these regions representing stable nuclides. The unbroken line passing below many of the nuclides represents the theoretical… …   Wikipedia

  • Global meteoric water line — The Global Meteoric Water Line is an equation defined by the geochemist Harmon Craig [cite journal|journal=Scripps News|url=http://scrippsnews.ucsd.edu/Releases/?releaseID=550|date=18 March 2003|title= Obituary notice: pioneer of geochemistry:… …   Wikipedia

  • separation and purification — ▪ chemistry Introduction       in chemistry, separation of a substance into its components and the removal of impurities. There are a large number of important applications in fields such as medicine and manufacturing. General principles… …   Universalium

  • Magnesium transporter — This page links directly from the magnesium in biological systems page. Magnesium transporters are proteins that transport magnesium across the cell membrane. All forms of life require magnesium, yet the molecular mechanisms of Mg2+ uptake from… …   Wikipedia

  • gas — gasless, adj. /gas/, n., pl. gases, v., gassed, gassing. n. 1. Physics. a substance possessing perfect molecular mobility and the property of indefinite expansion, as opposed to a solid or liquid. 2. any such fluid or mixture of fluids. 3. any… …   Universalium


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.