definite proportions, law of
- definite proportions, law of
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statement that every chemical compound contains fixed and constant proportions (by weight) of its constituent elements. Although many experimenters had long assumed the truth of the principle in general, the French chemist Joseph-Louis Proust (
Proust, Joseph-Louis) first accumulated conclusive evidence for it in a series of researches on the composition of many substances, especially the oxides of iron (1797). Another French chemist, Claude Berthollet, who held for indefinite proportions, contested Proust's findings, but the Scottish chemist Thomas Thomson confirmed some of them and wrote in his article “Chemistry” in the
Supplement to the
Encyclopædia Britannica (1801) that Proust had definitely proved “metals are not capable of indefinite degrees of oxidation.” The principle was then concretely formulated by the English chemist John Dalton in his chemical atomic theory (1808).
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Universalium.
2010.
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Law of definite proportions — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
Law of definite proportions — In chemistry, the law of definite proportions, sometimes called Proust s Law, states that a chemical compound always contains exactly the same proportion of elements by mass. An equivalent statement is the law of constant composition, which… … Wikipedia
law of definite proportions — law of def·i·nite pro·por·tions def (ə )nət prə pȯr shənz n a statement in chemistry: every definite compound always contains the same elements in the same proportions by weight * * * any compound always contains the same kind of elements in the … Medical dictionary
law of definite proportions — noun (chemistry) law stating that every pure substance always contains the same elements combined in the same proportions by weight • Syn: ↑law of constant proportion • Topics: ↑chemistry, ↑chemical science • Hypernyms: ↑law, ↑ … Useful english dictionary
law of definite proportions — Date: 1830 a statement in chemistry: every definite compound always contains the same elements in the same proportions by weight … New Collegiate Dictionary
Law of multiple proportions — In chemistry, the law of multiple proportions is one of the basic laws and a major tool of chemical measurement (stoichiometry). It states that when elements combine they do so in a ratio of small whole numbers. For example, carbon and oxygen… … Wikipedia
law of nature — noun a generalization that describes recurring facts or events in nature (Freq. 3) the laws of thermodynamics • Syn: ↑law • Hypernyms: ↑concept, ↑conception, ↑construct • … Useful english dictionary
Definite — Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or interval. [1913 … The Collaborative International Dictionary of English
Definite article — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
Definite inflorescence — Definite Def i*nite, a. [L. definitis, p. p. of definire: cf. F. d[ e]fini. See {Define}.] 1. Having certain or distinct; determinate in extent or greatness; limited; fixed; as, definite dimensions; a definite measure; a definite period or… … The Collaborative International Dictionary of English
