hydrogen ion

hydrogen ion
ionized hydrogen of the form H+, found in aqueous solutions of all acids.
[1895-1900]

* * *

      strictly, the nucleus of a hydrogen atom separated from its accompanying electron. The hydrogen nucleus is made up of a particle carrying a unit positive electric charge, called a proton (q.v.). The isolated hydrogen ion, represented by the symbol H+, is therefore customarily used to represent a proton. Because the bare nucleus can readily combine with other particles (electrons, atoms, and molecules), the isolated hydrogen ion can exist only in a nearly particle-free space (high vacuum) and in the gaseous state.

      In common usage, the term hydrogen ion is used to refer to the hydrogen ion present in water solutions, in which it exists as the combined molecule H+·H2O.

      The formula H+·H2O is also commonly written as H3O+ and denotes the hydronium or oxonium ion. The amount of hydrogen ion present in a water solution is used as a measure of the acidity of a substance; the higher the concentration of hydrogen ion the more acidic the solution and the lower the pH. See also pH.

* * *


Universalium. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Hydrogen ion — is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. [ Compendium of Chemical Terminology , 2nd edition McNaught, A.D. and Wilkinson, A. Blackwell Science, 1997 [ISBN 0 86542 684 8] , also… …   Wikipedia

  • Hydrogen ion — Hydrogen er et grundstof. Et hydrogen atom angives tit bare med et H. Hvis hydrogen atomet mangler en elektron, vil det gerne reagere med andre grundstoffer og molekyler. Når det sker kaldes hydrogen i stedet for en hydrogen ion. En hydrogen ion… …   Danske encyklopædi

  • hydrogen ion — or hydrogen n. 1. the positively charged nucleus of hydrogen, H+, without its electron 2. HYDRONIUM ION …   English World dictionary

  • hydrogen ion — n 1) the cation H+ of acids consisting of a hydrogen atom whose electron has been transferred to the anion of the acid 2) HYDRONIUM * * * the nucleus of the hydrogen atom or a hydrogen atom that has lost its electron, H+; it bears a positive… …   Medical dictionary

  • hydrogen ion — noun a positively charged atom of hydrogen; that is to say, a normal hydrogen atomic nucleus • Hypernyms: ↑proton, ↑cation • Part Holonyms: ↑hydrogen atom * * * noun 1. : the cation H+ of acids consisting of a hydrogen atom wh …   Useful english dictionary

  • hydrogen ion concentration — hydrogen ion concentration. См. водородный показатель. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • hydrogen ion concentration — pH (a measure of how acidic or alkaline a solution is, i.e. the concentration of hydrogen ions in a solution (log to base 10 of the reciprocal of the hydrogen ion concentration). pH 7.0 is neutral, lower values are acidic and higher values are… …   Dictionary of ichthyology

  • hydrogen-ion concentration — noun : the concentration of hydrogen ions in a solution expressed usually in moles per liter or in pH units and used as a measure of the acidity of the solution indicator dyes for narrow ranges of hydrogen ion concentration …   Useful english dictionary

  • hydrogen ion concentration — noun the number of moles of hydrogen ion in a litre of solution; a measure of the acidity or alkalinity of a solution. See pH …  

  • hydrogen ion exponent — vandenilio jonų rodiklis statusas T sritis Standartizacija ir metrologija apibrėžtis Vandenilio jonų koncentracijos neigiamas dešimtainis logaritmas. atitikmenys: angl. hydrogen ion exponent vok. Wasserstoffionenexponent, m rus. водородный… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

Share the article and excerpts

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