When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Pyramidal inversion - Wikipedia

    en.wikipedia.org/wiki/Pyramidal_inversion

    Pyramidal inversion in nitrogen and amines is known as nitrogen inversion. [8] It is a rapid oscillation of the nitrogen atom and substituents, the nitrogen "moving" through the plane formed by the substituents (although the substituents also move - in the other direction); [ 9 ] the molecule passing through a planar transition state . [ 10 ]

  3. Glossary of chemistry terms - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_chemistry_terms

    Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...

  4. Umpolung - Wikipedia

    en.wikipedia.org/wiki/Umpolung

    In organic chemistry, umpolung (German: [ˈʔʊmˌpoːlʊŋ]) or polarity inversion is the chemical modification of a functional group with the aim of the reversal of polarity of that group. [ 1 ] [ 2 ] This modification allows secondary reactions of this functional group that would otherwise not be possible. [ 3 ]

  5. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    Substitution reactions in organic chemistry are classified either as electrophilic or nucleophilic depending upon the reagent involved, whether a reactive intermediate involved in the reaction is a carbocation, a carbanion or a free radical, and whether the substrate is aliphatic or aromatic. Detailed understanding of a reaction type helps to ...

  6. Suspension (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Suspension_(chemistry)

    In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye , usually must be larger than one micrometer , and will eventually settle , although the mixture is only classified as a suspension when and while the particles have ...

  7. Talk:Anatomical terms of motion - Wikipedia

    en.wikipedia.org/wiki/Talk:Anatomical_terms_of...

    Could the difference between inversion/eversion and pronation/supination of the foot please be clarified? As far as I can tell, the definitions given in the article are synonymous with each other: Pronation of the foot refers to turning of the sole outwards, so that weight is borne on the medial part of the foot.

  8. Walden inversion - Wikipedia

    en.wikipedia.org/wiki/Walden_inversion

    In the Walden inversion, the backside attack by the nucleophile in an S N 2 reaction gives rise to a product whose configuration is opposite to the reactant. Therefore, during S N 2 reaction, 100% inversion of product takes place. This is known as Walden inversion. It was first observed by chemist Paul Walden in 1896.

  9. Intimate ion pair - Wikipedia

    en.wikipedia.org/wiki/Intimate_ion_pair

    In chemistry, the intimate ion pair concept, introduced by Saul Winstein, describes the interactions between a cation, anion and surrounding solvent molecules. [1] In ordinary aqueous solutions of inorganic salts, an ion is completely solvated and shielded from the counterion. In less polar solvents, two ions can still be connected to some extent.