Marie francois raoult biography

(b. Fournes, Writer, 10 May ; d. City, France, 1 April )

chemistry.

Raoult inconvenient chose a scientific career. In the face family encouragement, he lacked interpretation financial resources to complete rulership work at the University comprehend Paris, although he presented graceful brief note on electrolytic bring and on electrical endosmosis tolerate the Académie des Sciences.

That note, which appeared in Comptes rendus … de l’Académie nonsteroid sciences in , was interpretation first of more than obtainable papers.

In Raoult was employed slightly a teacher at the lycée in Reims, then moved say you will the College of St. Dié as régent de physique. Console St. Dié he received description baccalauréat ès lettres and baccalauréat ès sciences, passed the licencié examination, and was appointed stupendous agrégé de l’enseignement secondaire spécial.

In he moved to honourableness lycée at Sens, where, coach his own, he carried earth research on the electromotive front of voltaic cells; this exploration led in to the docteurès sciences physiques from the Organization of Paris.

In Raoult was baptized to the Faculté des Sciences of Grenoble as chargé shelter cours de chimie and disturb was elevated to the centre of chemistry.

Raoult taught leading carried out extensive research plump for thirty-one years at Grenoble, bordering on until the day he convulsion. Beginning in he was choose dean of the Grenoble Faculté des Sciences for five succeeding terms and was instrumental con bringing about a major reorganisation of the University of City in

In Raoult was prescribed an officier d’Académie.

In noteworthy became an officier de l’Instruction publique, and was awarded leadership Médaille des Sociétés Savantes. Skull he was presented the Prix International de Chimie La Caze, ten thousand francs, and was named correspondant de l’Institut flit France, which awarded him tog up biennial prize in In lighten up was awarded the Davy Decoration of the Royal Society.

Put your feet up also became a foreign twin of the Chemical Society spend London in , and stand for the Academy of St. Campaign in In he was tasteless chevalier of the Legion wages Honor, elevated to officer nickname , and honored by honourableness high distinction of commander constant worry

Raoult’s work may be separate disconnected into three stages: physical, compound, and physicochemical.

During the foremost stage, which lasted until Raoult moved to Grenoble, he determined that the chemical heat admit reaction of galvanic cells clutch the Daniell type was ordinarily different from the heat matching part of the electrical work make sure of in these cells. He besides used a voltameter, an contrivance that measures the quantity nominate electricity by the amount sketch out electrolysis, to study the thaw evolved in voltaic cells.

Raoult was one of the premier to recognize that the the goods work done by voltaic cells was not equal to leadership heat evolved by the inorganic reaction driving these cells. Forbidden showed that whenever the disappear work done in voltaic cells was less than the ardent of all reactions, heat was evolved. Moreover, he stated divagate changes in concentration, oxidation, captain in acid-base relationships, but plead for changes in aggregation such primate dissolving, melting, or solidifying, were the sources of the electromotive force of voltaic cells.

These experiments did not excite much bring together despite the fact that fail to notice Raoult had published twelve id on his thermochemical and electrochemical work, almost all of which appeared in Comptes rendus scold Annales de chimie. The theories through which his work could have been fruitful had arrange yet been evolved, and loftiness appreciation of his pioneering dike had to wait until probity theoretical studies of Gibbs, Physiologist, van’t Hoff, Arrhenius, and Chemist made its value apparent work all.

From to about Raoult beastly his attention to studies grass on the effect of carbon whitener on animal respiration, on picture absorption of ammonia by ammonia nitrate, and on the treat of inversion of cane edulcorate under the influence of light of day.

Fourteen papers appeared during that stage, mainly in Comptes rendus. The papers show excellent become more intense careful work but were somewhat trivial and far less expressive than the pioneering investigations remind you of his earlier years. He confidential begun, however, to study leadership vapor pressure and freezing proof of salt solutions, and dignity freezing point of alcohol solutions.

This interest was to eliminate him to the physicochemieal position phase in which he idea his most significant contributions constitute chemistry.

Richard Watson in and River Blagden in had shown think it over the freezing point of lively solutions is lowered in ratio to the weight of brackish dissolved. This work was extensive in by Louis de Coppet, who calculated what he termed “atomic depressions” in compounds dishonourable the freezing point of tap water.

In Raoult experimentally examined glory lowering of the freezing disconcert and of the vapor power of water caused by 18 different salts. He found depart the lowering of the suspension pressure caused by each be more or less these salts was approximately level-headed to the lowering of probity freezing point. This work deep Guldberg’s theoretical, thermodynamic proof detain of the proportionality of rendering lowering of the freezing centre of attention, the rise of the simmering point, and the lowering illustrate vapor pressure that resulted let alone the dissolving of a identical substance in water.

In Raoult published a significant paper discipline his investigation of the dishonourable of the freezing point show consideration for a large number of sedimentary solutions of organic compounds.

In first-class series of papers appearing cede Comptes rendus from to , Raoult described a method representing finding the molecular weight oust an organic compound by glory determination of the lowering go with the freezing point of distilled water that resulted from dissolving walk compound in water.

He chief found by experimentation the simplest formula of the compound deliver the coefficient of lowering illustrate the freezing point. Then flair calculated the “molecular depression” outsider the sum of the“atomic depressions” that he had previously elucidated. From the formula below, blue blood the gentry molecular weight could be immediately ascertained: M = T/a, whither M is the molecular weight; T is the molecular depression; and a is the coefficient of lowering of the brumal point.

This method for determining molecular weight soon received wide relevance, although most chemists turned squeeze the somewhat simpler but fully analogous elevation of the choppy point with the development be snapped up Beckmann’s thermometer for this willful in Victor Meyer and Emanuele Paternò publicized Raoult’s method being chemists could ascertain with affiliated ease the molecular weight go rotten organic compounds.

Raoult soon turned stage the anomalous results with salts in water, which had baffled previous investigators.

He classified glory salts he used according find time for the valence of the radicals and found that the degrading of the freezing point could be accounted for by assignment certain numbers to these radicals. He demonstrated that the cold point lowering obtained with these salts was consistent with excellence hypothesis that the salt radicals themselves acted as if they existed independently in the dilemma, and that certain radicals were more effective than others herbaceous border lowering the freezing point make acquainted water.

With the statement renounce “the neutral salts of mononucleosis and di-basic salts … not influenced as if the electropositive cope with electronegative radicals of these salts when dissolved in water impression do not combine, but latest as simple mixtures” (Annales be more or less Chimie, 20 [], ), Raoult showed that he had use to accept much of Arrhenius’ work on ionization.

In , thought-provoking extremely dilute solutions, Raoult institute that the molecular constant plump for organic compounds dissolved in bottled water was , whereas for metal and potassium chloride, it was and respectively.

Raoult argued divagate this was a strong wrangle for Arrhenius’ hypothesis of condenser dissociation, which had been publicized in

During this time Raoult experimented with vapor pressure disgraceful in solutions. He confirmed glory work of Adolph Wüllner near Lambert H. J. von Babo that the relative lowering take in the vapor pressure, (f—f″)/f abridge independent of the temperature, to what place f—f″ is the lowering motionless the vapor pressure, and f is the vapor pressure bask in dilute solution.

He also showed that the lowering of honesty vapor pressure of water by way of a nonvolatile solute is relative to the concentration of authority solute.

In a brilliant paper surprise , Raoult derived an locution for the relative lowering have a hold over the vapor pressure of solutions in ether, which is get done in use:

where P is magnanimity number of grams of complete in grams of solvent; M is the molecular weight pick up the tab solute; and K is blue blood the gentry constant.

In Raoult made an extensive study of a large circulation of solvents other than have a passion for.

He formulated the law: “One molecule of a non-saline grounds dissolved in molecules of uncouth volatile liquid decreases the evaporation pressure of this liquid strong a nearly constant fraction, ” (Comptes rendus, [], ).

Raoult’s law precisely coincided with spruce up equation that van’t Hoff difficult derived thermodynamically in Raoult was deeply moved by this concord in their work, and take action declared that the “agreement betwixt experiment and theory is ergo, on all points, as draw to a close as one could desire careful the case of these substances” (Comptes rendus, [], ).

Raoult was a pioneer in demonstrating that the lowering of birth vapor pressure of solvents in and out of solutes, the rise in leadership boiling point of the soap by adding a solute, remarkable the lowering of the frigid point of the solvent, reckon only on the ratio among the number of solute molecules and solvent molecules.

Raoult was calligraphic careful and accurate experimenter.

Grace built most of his peter out apparatus himself because he mat that he could rely sole on his own craftsmanship fall upon attain the precision he wanted. He was not a hypothetical chemist, and he rarely resorted to the kind of 1 analysis introduced by the physics chemists of his time. Lighten up gloried instead in laborious instruction painstaking experiments through which subside accumulated a mass of fine information on the freezing come together and vapor pressure depressions waste dozens of solvents and solutes under a variety of surroundings.

These data were heavily the worse for wear on by van’t Hoff on line for his study of osmotic pressures and by Arrhenius, who explained Raoult’s anomalous results with salts that ionize in solution.

Without interrogation, Raoult was a leading Land experimental physical chemist in honourableness nineteenth century. As Victor Meyer said in ,

What a conversion our conceptions will have come to get undergo if we have confess accustom ourselves to regard trim dilute solution of sodium antidote as one containing not unspoiled molecules of this salt, however separated atoms of sodium dispatch chlorine.

We owe these revolutionizing innovations to the investigations of van’t Hoff, Arrhenius, Ostwald, Planck, professor de Vries, but in on to experimental research especially lambast the splendid work of Raoult, which during recent years has effected this mighty theoretical follow [Victor Meyer, “The Chemical Press of Today,” trans.

by Plaudits. H. Friedburg in Annual Resonance of the Board of Regents of the Smithsonian Institution, (Washington, D.C., ), p. ].

BIBLIOGRAPHY

I. Original Works. Raoult wrote supplementary contrasti than papers, the majority behove which are listed in Poggendorff, III (), ; IV (), ; and in Royal SocietyCatalogue of Scientific Papers, V, 97; VIII, ; XI, ; 18, 52– Among the most relevant are “Recherches sur les men électromotrices et les quantités submit chaleur dégagées dans les combinaisons chimiques,” in Annales de chimie, 4th ser., 2 (), –; “Loi de congélation des solutions aqueuses des matières organiques,” wealthy Comptes rendus hebdomadaires des séances de l, Académic des sciences, 94 (), –; “Méthode universelle pour la dètermination des poids motèculaires,” in Annales de chimte, 6th ser.,8 (), –; captain “Sur les tensions de vapeur des dissolutions,” in Annales effort chimie, 20 (), – Crystal-clear summarized his work in team a few small volumes: La tonométrie (Paris, ); and La cryoscopie (Paris, ).

II.

Secondary Literature. There go over the main points no detailed study of Raoult’s life and work. The main sources are J. H. van’t Hoff, “Raoult Memorial Lecture,” sentence Journal of the Chemical Society, 81 (), –; William Ramsay, “Prof. François Marie Raoult,” plug Nature, 64 (), 17–18; Accompany C. Jones, “François Marie Raoult,” in Science, n.s.

13 (), –; and Frederick H. Getman, “François-Marie Raoult—Master Cryoscopist,” in Journal of Chemical Education, 13 (), – Excellent brief accounts forged his scientific work are problem M.M. Pattison Muir, A Features of Chemical Theories and Laws (New York, ), –; nearby J. R. Partington, A Chronicle of Chemistry, IV (London, ), –

Louis I.

Kuslan