A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction or is added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of a chemical reaction". Solvents and catalysts, although they are involved in the reaction, are usually not referred to as reactants.
In organic chemistry, reagents are compounds or mixtures, usually composed of inorganic or small organic molecules, that are used to affect a transformation on an organic substrate. Examples of organic reagents include the Collins reagent, Fenton's reagent, and Grignard reagent. There are also analytical reagents which are used to confirm the presence of another substance. Examples of these are Fehling's reagent, Millon's reagent and Tollens' reagent.
In another use of the term, when purchasing or preparing chemicals, reagent-grade describes chemical substances of sufficient purity for use in chemical analysis, chemical reactions or physical testing. Purity standards for reagents are set by organizations such as ASTM International. For instance, reagent-quality water must have very low levels of impurities like sodium and chloride ions, silica, and bacteria, as well as a very high electrical resistivity.
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Reagent — Re*a gent (r[ e]*[=a] jent), n. (Chem.) A substance capable of producing with another a reaction, especially when employed to detect the presence of other bodies; a test. [1913 Webster] … The Collaborative International Dictionary of English
reagent — REAGÉNT s. v. agent chimic, reactiv. Trimis de siveco, 05.08.2004. Sursa: Sinonime … Dicționar Român
reagent — (n.) 1797, from RE (Cf. re ) + AGENT (Cf. agent) substance that produces a chemical reaction … Etymology dictionary
reagent — ► NOUN ▪ a substance or mixture for use in chemical analysis or other reactions … English terms dictionary
reagent — [rē ā′jənt] n. [ RE + AGENT] Chem. a substance used to detect or measure another substance or to convert one substance into another by means of the reaction which it causes … English World dictionary
reagent — UK [rɪˈeɪdʒ(ə)nt] / US [rɪˈeɪdʒənt] noun [countable] Word forms reagent : singular reagent plural reagents chemistry a substance used in a chemical reaction … English dictionary
reagènt — ênta in énta m (ȅ é, ẹ) kem. snov, s katero se po značilnih reakcijah ugotavljajo vrste sestavin kake snovi: dodati raztopini reagent / kemični reagenti ♦ mont. flotacijski reagent ki se pri flotaciji dodaja vodi … Slovar slovenskega knjižnega jezika
reagent — cheminis reagentas statusas T sritis chemija apibrėžtis Grynas cheminis junginys, griežtai nustatytos sudėties mišinys ar tirpalas, vartojamas analizei ir tyrimams. atitikmenys: angl. chemical reagent; reagent rus. реагент; реактив; химический… … Chemijos terminų aiškinamasis žodynas
reagent — noun Etymology: New Latin reagent , reagens, present participle of reagere to react more at react Date: 1797 a substance used (as in detecting or measuring a component, in preparing a product, or in developing photographs) because of its chemical … New Collegiate Dictionary
reagent — [[t]rie͟ɪʤənt[/t]] reagents N COUNT A reagent is a substance that is used to cause a chemical reaction. Reagents are often used in order to indicate the presence of another substance. [TECHNICAL] … English dictionary