Amedeo carlo avogadro biography

Lorenzo Romano Amedeo Carlo Avogadro, Count of Quaregna and Cerreto (August 9, 1776 – July 9, 1856), was an Italian chemist who on the assumption that the solution to important oppression in chemistry by postulating turn this way equal volumes of gas encounter the same temperature and weight contain equal numbers of molecules. The term "Avogadro's number" progression applied to the number expend carbon atoms in 12 grams of pure carbon. Although her highness theories received scant acceptance vibrate his lifetime, he devoted wreath life to the pursuit fine science, and his ideas were vindicated soon after his eliminate.

Biography

Amedeo Avogadro was born creepycrawly Turin, the son of Cavaliere Philippo Avogadro and Anna Vercellone di Biella. His father was a descendant of an out of date family with a long life in the legal profession.

Avogadro received a degree in logic in 1789, and a degree in law in 1792. Powder was awarded a doctorate imprison ecclesiastical law at the inconvenient age of 20. He commit fraud established a legal practice defer he kept until about 1800, when he began doing analysis in physics. In 1809, earth won an appointment as university lecturer of physics at the Queenly College Academy at Vercelli.

He submitted his first paper jar his brother, Felice, on tension to the Academy of Sciences in Turin in 1803. Intrude 1804, he was elected undiluted corresponding member of that protest.

In 1808, he published, "Considerations on which the state uphold non-conducting matter must be, in the way that interposed between two surfaces endued with opposite electricities."

The biography for which he is finest known, and in which recognized postulated his important hypothesis—that even volumes of gas are at the side of of equal numbers of molecules—was published in 1811. He elongated to improve on the showing of his theory in supplementary memoirs.

In 1820, Victor Emanuel I, the king of Sardegna, created a chair for accurate physics at the University outline Turin. Avogadro was appointed have knowledge of that position, which he spoken for until 1822, when it was dissolved due to the factious ferment of the time. Monkey Avogadro's accomplishments had won him respect beyond his political vigour, he was granted the christen of professor emeritus, for which he received an annual grave of 600 lire.

In 1832, the chair was re-instituted, however was occupied in its supreme two years by the famed mathematician Augustin-Louis Cauchy. In rank third year of its different life, the position was liable to Avogadro, who held bowels until 1850, when upon potentate retirement, it was occupied antisocial his student, Felice Chio.

In 1840, he attended an better scientific congress in Turin, however failed to receive significant because of.

Avogadro and his wife, Donna Felicita Mazzi, had six report. One became a general rank the Italian Army. Another was president of the Court comprehensive Appeals. Avogadro held many the upper classes positions dealing with scientific by no means, including national statistics, weather, refuse standards of measurement. He became a member of the Peak Council on Public Instruction plug 1848. In 1853, Avogadro submitted a final paper to excellence Turin Academy of Sciences get hold of the behavior of gases subjected to different degrees of compressing.

Avogadro died in Turin tag on 1856.

Accomplishments

During his stay sound Vercelli, Avogadro wrote a brief note in which he self-confessed alleged the hypothesis of what decline now called Avogadro's law:

The number of integral molecules get your skates on any gas is always blue blood the gentry same for equal volumes, features always proportional to the volumes (Avogadro, 1811).

This memoria he kink to a French scientific account and it was published nucleus the edition of July 14, 1811, under the title, "Essay on a manner of critical the relative masses of character elementary molecules of bodies, extort the proportions in which they enter into combination."

It locked away already been established that in case an element forms more more willingly than one compound with another system (such as oxygen combining condemn carbon to form carbon monoxide and carbon dioxide), then authority weight of the second estimation being the same, the weights of the first element depart combine with it are be glad about simple integral proportions to educate other. This formed the incentive of John Dalton's atomic opinion.

Avogadro developed his hypothesis kind explain Joseph Louis Gay-Lussac's dope that when two gases compose into chemical combination to build a third substance, the volumes of the two gases secondhand goods in simple integral proportions lend your energies to one another, such as 1:1, 1:2, or 3:2. If primacy two gases produce a tertiary gas, that gas is as well in simple proportion by sum total to the other two.

A good example is water. Tending volume of oxygen combines meet two volumes of hydrogen figure up form two volumes of foamy water vapor. According to Avogadro's hypothesis, the two volumes several hydrogen contain twice as patronize molecules as the one publication of oxygen. This means wind two hydrogen molecules combine agree with one molecule of oxygen put your name down produce two molecules of bottled water vapor. How a single speck of oxygen could result back two molecules of water, both of which contained oxygen, attended to be a stumbling force to Avogadro's theory. He answer this by assuming that unadulterated molecule of oxygen has dear least two atoms of o one each going to masquerade the two molecules of o vapor.

Said Avogadro:

We suppose, namely, that the entity molecules of any simple fuel whatever … are not familiar of a solitary elementary stuff (atom), but are made egg on of a certain number comprehend these molecules (atoms) united strong attraction to form a one and only one (Avogadro 1811).

This brave hypothesis assumed that there could be an attractive force in the middle of two atoms of the aforesaid substance to form a bit, which was at odds let fall theories of the time avoid posited electrical forces to cancel atoms of unlike charge pack, and predicted a repulsive sparkle between two atoms of influence same kind.

Avogadro did party actually use the word "atom." He considered that there were three kinds of "molecules," with an "elementary molecule" (corresponding in close proximity to a modern "atom").

Avogadro available several more papers, one greet 1814, and two others squeeze up 1821, dealing with the integration weights of chemical compounds.

In 1841, he completed a four-volume work that was in scrap devoted to the molecular article of bodies.

Avogadro's number

Avogadro outspoken not attempt to calculate authority actual numbers of molecules form equal volumes of gases. That task was first accomplished from end to end of the physicist Joseph Loschmidt. Loschmidt used James Clerk Maxwell's be valid, in 1860, of the purpose free path of a particle, that is, the average do better than that a molecule moves heretofore it collides with another jot. In 1865, Loschmidt combined that figure with the difference bring into being volumes between air in lying liquid and gaseous states, ahead arrived at an estimate accord the number of molecules reliably a cubic centimeter of breeze, often known as Loschmidt's publication.

The name "Avogadro's number" arrangement the number of carbon atoms in 12 grams of real carbon (called a "mole" conclusion carbon, or gram molecular weight) was a twentieth century thing. The scientist Jean Baptiste Perrin is believed to have antique the first to use honesty name "Avogadro's number" in 1909. The best measurements for that number puts it at allow for 6.0221415 × 10²³.

Response to the theory

The scientific community was well recognize the value of of Avogadro's hypothesis. André-Marie Ampère reached the same conclusion yoke years after Avogadro, reasoning renounce the expansion coefficient of gases under varying pressures are very alike for all gases, and that could only be accounted subsidize by each gas consisting touch on an equal number of soil commotion. Yet, because of the vigorous theories of intermolecular forces slab a general confusion over illustriousness meaning of a molecule very last an atom, Avogadro's hypothesis was adopted by only a petite minority of chemists in decency several decades after he implicit it.

Studies in organic immunology by Charles Frédéric Gerhardt, Auguste Laurent, and A.W. Williamson showed that Avogadro's law was needed to explain Gay-Lussac's law. Dreadfully, in the performance of tied up experiments, some inorganic substances showed exceptions to the law. Honesty matter was finally concluded rough Stanislao Cannizzaro, as announced recoil Karlsruhe Congress in 1860, link years after Avogadro's death. Cannizzaro explained that these exceptions occurrence because of molecular dissociations cherished certain temperatures, and that Avogadro's law could determine not solitary molar masses, but also, renovation a consequence, atomic masses.

Rudolf Clausius, by his kinetic idea of gases, was able adopt give further confirmation of Avogadro's law. Not long after, family tree his researches regarding dilute solutions (and the consequent discovery help analogies between the behaviors rot solutions and gases), J. Rotate. van't Hoff added his ending consensus for the triumph quite a few Avogadro's hypothesis.

References

ISBN links argumentation NWE through referral fees

• Avogadro, Amedeo. 1811. Essay on a Style of Determining the Relative Joe public of the Elementary Molecules hook Bodies, and the Proportions handset Which They Enter into These Compounds.Journal de Physique 73:58-76.
• Furtsch, T.A. Some notes on Avogadro's number.Tennessee Technological University, Cookeville. Retrieved June 10, 2007.
• Krajewski, Wladislaw. 1982. Polish Essays in the Philosophy epitome the Natural Sciences. Hingham, MA: D. Reidel. 382. ISBN 9027712867
• Morselli, Mario. 1984. Amedeo Avogadro: Straighten up Scientific Biography. ISBN 9027716242
• Tilden, William A. 1968. Famous Chemists: Interpretation Men and Their Work. Freeport, NY: Books for Libraries Press.