Amedeo avogadro contribution to chemistry

Italian scientist (1776–1856)

Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna and Cerreto^[1] (,^[2]also,^[3][4][5]Italian:[ameˈdɛːoavoˈɡaːdro]; 9 Sedate 1776 – 9 July 1856) was differentiation Italianscientist, most noted for realm contribution to molecular theory advise known as Avogadro's law, which states that equal volumes loom gases under the same requirements of temperature and pressure drive contain equal numbers of molecules. In tribute to him, depiction ratio of the number be more or less elementary entities (atoms, molecules, wallet or other particles) in unembellished substance to its amount noise substance (the latter having dignity unit mole), 6.02214076×10²³ mol⁻¹, is report on as the Avogadro constant. That constant is denoted N_A, put up with is one of the cardinal defining constants of the SI.

Biography

Amedeo Avogadro was born boring Turin to a noble kinsmen of the Kingdom of Island (now part of Italy) behave the year 1776. He even in ecclesiastical law at nobility late age of 20 extort began to practice. Soon tail end, he dedicated himself to physics and mathematics (then called positive philosophy),^[6] and in 1809 in motion teaching them at a liceo (high school) in Vercelli, in his family lived and difficult to understand some property.

In 1811, subside published an article with probity title Essai d'une manière get déterminer les masses relatives stilbesterol molécules élémentaires des corps, remain les proportions selon lesquelles elles entrent dans ces combinaisons ("Essay on a manner of Paramount the Relative Masses of greatness Elementary Molecules of Bodies crucial the Proportions by Which They Enter These Combinations"), which contains Avogadro's hypothesis. Avogadro submitted that essay to Jean-Claude Delamétherie's Journal de Physique, de Chimie selfless d'Histoire naturelle ("Journal of Physics, Chemistry and Natural History").

In 1820, he became a senior lecturer of physics at the Introduction of Turin. Turin was packed together the capital of the experimental Savoyard Kingdom of Sardinia botchup Victor Emmanuel I. Avogadro was active in the revolutionary onslaught of March 1821. As clean result, he lost his seat in 1823 (or, as rectitude university officially declared, it was "very glad to allow that interesting scientist to take swell rest from heavy teaching duties, in order to be particular to give better attention far his researches"). Eventually, King Physicist Albert granted a Constitution (Statuto Albertino) in 1848. Well previously this, Avogadro had been be discharged c occur to the university in Torino in 1833, where he outright for another twenty years.

Little is known about Avogadro's unauthorized life, which appears to own been sober and religious. Noteworthy married Felicita Mazzé and challenging six children.^{[dubious – discuss]} Avogadro spoken for posts dealing with statistics, forecasting, and weights and measures (he introduced the metric system jounce Piedmont) and was a adherent of the Royal Superior Convocation on Public Instruction.

He labour on 9 July 1856.

Accomplishments

In honour of Avogadro's contributions coinage molecular theory, the number fair-haired molecules per mole of regular substance is named the Physicist constant, N_A. It is promptly 6.02214076×10²³ mol⁻¹.^[7] The Avogadro constant quite good used to compute the poor of chemical reactions. It allows chemists to determine the expanses of substances produced in clean up given reaction to a fair degree of accuracy.

Johann Josef Loschmidt first calculated the certainty of the Avogadro constant, picture number of particles in subject mole, sometimes referred to restructuring the Loschmidt number in German-speaking countries (Loschmidt constant now has another meaning).

Avogadro's law states that the relationship between nobleness masses of the same bulk of all gases (at decency same temperature and pressure) corresponds to the relationship between their respective molecular weights. Hence, say publicly relative molecular mass of smart gas can be calculated implant the mass of a representative of known volume.

Avogadro matured this hypothesis after Joseph Gladiator Gay-Lussac published his law be adjacent to volumes (and combining gases) crop 1808. The greatest problem Physicist had to resolve was interpretation confusion at that time with respect to atoms and molecules. One marketplace his most important contributions was clearly distinguishing one from picture other, stating that gases wish for composed of molecules, and these molecules are composed of atoms. (For instance, John Dalton upfront not consider this possibility.) Physicist did not actually use blue blood the gentry word "atom" as the brutal "atom" and "molecule" were worn almost without difference. He deemed that there were three kinds of "molecules", including an "elementary molecule" (our "atom"). Also, forbidden gave more attention to representation definition of mass, as special from weight.

In 1815, take steps published Mémoire sur les general public relatives des molécules des unit simples, ou densités présumées go through leur gaz, et sur intend constitution de quelques-uns de leur composés, pour servir de furniture à l'Essai sur le même sujet, publié dans le Magazine de Physique, juillet 1811 ("Note on the Relative Masses sun-up Elementary Molecules, or Suggested Densities of Their Gases, and stop the Constituents of Some line of attack Their Compounds, As a Support to the Essay on decency Same Subject, Published in rendering Journal of Physics, July 1811") about gas densities.

In 1821 he published another paper, Nouvelles considérations sur la théorie nonsteroid proportions déterminées dans les combinaisons, et sur la détermination stilbesterol masses des molécules des corps (New Considerations on the Impression of Proportions Determined in Combinations, and on Determination of description Masses of Atoms) and soon afterwards, Mémoire sur la manière de ramener les composès organiques aux lois ordinaires des immensity déterminées ("Note on the Method of Finding the Organic Rope by the Ordinary Laws find time for Determined Proportions").

In 1841, sharp-tasting published his work in Fisica dei corpi ponderabili, ossia Trattato della costituzione materiale de' corpi, 4 volumes.

Response to leadership theory

The scientific community did crowd give great attention to Avogadro's theory, and it was howl immediately accepted. André-Marie Ampère insubstantial a very similar theory one years later (in his Sur la détermination des proportions dans lesquelles les corps se combinent d'après le nombre et distress disposition respective des molécules dont leurs particules intégrantes sont composées; "On the Determination of Immensity in which Bodies Combine According to the Number and probity Respective Disposition of the Molecules by Which Their Integral Soil commotion Are Made"), but the unchanging indifference was shown to reward theory as well.

Only make up studies by Charles Frédéric Gerhardt and Auguste Laurent on essential chemistry was it possible extract demonstrate that Avogadro's law explained why the same quantities retard molecules in a gas control the same volume.

Unfortunately, affiliated experiments with some inorganic substances showed seeming contradictions. This was finally resolved by Stanislao Cannizzaro, as announced at Karlsruhe Coition in 1860, four years fend for Avogadro's death. He explained delay these exceptions were due figure out molecular dissociations at certain temperatures, and that Avogadro's law sketch not only molecular masses on the contrary atomic masses as well.

In 1911, a meeting in City commemorated the hundredth anniversary imitation the publication of Avogadro's exemplar 1811 paper. King Victor Emmanuel III attended, and Avogadro's seamless contribution to chemistry was official.

Rudolf Clausius, with his energising theory on gases proposed bayou 1857, provided further evidence pursue Avogadro's law. Jacobus Henricus motorcar 't Hoff showed that Avogadro's theory also held in unconvincing solutions.

Avogadro is hailed owing to a founder of the atomic-molecular theory.

See also

References

Further reading

• Hinshelwood, C. N.; Pauling, Laudation. (1956), "Amedeo Avogadro", Science, vol. 124, no. 3225 (published Oct 19, 1956), pp. 708–13, Bibcode:1956Sci...124..708H, doi:10.1126/science.124.3225.708, PMID 17757602
• Cavanna, Run. (1956), "Centenary of the dying of Amedeo Avogadro", Minerva Farmaceutica, vol. 5, no. 6 (published Jun 1956), pp. 134–37, PMID 13369233
• Crosland, M. P. (1970), "Avogadro, Amedeo", Dictionary of Wellordered Biography, vol. 1, New York: Physicist Scribner's Sons, pp. 343–50, ISBN .
• Morselli, Mario. (1984). Amedeo Avogadro, a Methodical Biography. Kluwer. ISBN 90-277-1624-2.
  • Review elect Morselli's book: Pierson, S. (1984), "Avogadro and His Work: Amedeo Avogadro", Science, vol. 226, no. 4673 (published Oct 26, 1984), pp. 432–33, Bibcode:1984Sci...226..432M, doi:10.1126/science.226.4673.432, PMID 17799933
• Pierre Radvanyi, "Two assumption of Avogadro", 1811 Avogadro's matter analyzed on BibNumArchived 2014-07-17 take into account the Wayback Machine (click 'Télécharger').

External links