Joseph Louis Gay-Lussac
Joseph Louis Gay -Lussac (December 6, 1778 in Saint- Léonard- de -Noblat; † May 9, 1850 in Paris) was a French chemist and physicist. He discovered the uniform thermal expansion of gases ( Gay -Lussac 's law). With Alexander von Humboldt, he measured the amount of gas in the electrolysis of water: hydrogen / oxygen = 2 /1, and the ratio of the quantities of gas to form water. He further notes that in the reaction of different gases, the volume fractions of the individual gases must be an integer multiple of ( law of multiple volumes). He also developed the first safe method to carry out elemental analysis of organic substances, and also that he introduced from a titrimetry ( volumetric analysis ).
Life
Joseph Gay - Lussac's father was a judge and was actually called Antoine Gay, a small estate in the vicinity of their residence was Lussac. Joseph Louis Gay -Lussac was the eldest child of the seven-member family in a small town in the French province of Limousin. In November 1794, he went to Paris; because of the famine, many students were sent back home to her parents - Gay -Lussac was allowed to stay because of its good mathematical skills. Since September 1797 he first attended the Polytechnic ( École Centrale des Travaux Publics ) and later the École Nationale des Ponts et Chaussées, where he made the acquaintance of Claude -Louis Berthollet. In 1802 he was polytechnique tutor for chemistry at the École and lectured in chemistry and a lecture at the Academy of Sciences.
Scientists interested in time for the direction of the magnetic needle, and the composition of the air in the higher layers of the atmosphere. Previously (1804 ) had already made the Academy in St. Petersburg first studies in a balloon. The Institut de France commissioned Gay -Lussac and Jean- Baptiste Biot, make measurements with a balloon.
On August 24, 1804, he undertook together with Biot a daring flight in a hydrogen balloon, reaching a height of 4,000 meters. On this occasion, both studied the Earth's magnetic field. On September 16, he undertook, this time alone, a second balloon ride. He took air samples at different heights and climbed to 21,600 feet up in Paris, which corresponds to 7,017 meters above the balloon site. The samples were analyzed together with Alexander von Humboldt showed that the oxygen content of the air does not change with height. They were able to measure a temperature decrease of 1 ° C per 174 meters ascent, also could Gay -Lussac and Alexander von Humboldt John Dalton's idea - that atomically heavier gases sink, lighter atomic gases rise, and this changes the composition in higher atmosphere - refute. Today we know that Dalton's assumption would result in, among other things, that the entire carbon dioxide content of the atmosphere would be pure gain to the earth's surface, which would suffocate oxygen consumers (eg all animals and humans). Nevertheless, the chemical composition of the atmosphere actually changes with altitude to a limited extent due to other physical influences, the density of the gas is irrelevant.
Berthollet founded a private institution of society, the Société d' Arcueil. There was Gay-Lussac in acquaintance with Laplace and Alexander von Humboldt. With this he undertook a research trip ( March 1805 ) to Rome and Naples ( Vesuvius ), they spent the winter 1805/1806 in Berlin.
In 1809 Gay -Lussac Professor of Chemistry and 1808 polytechnique as professor of practical chemistry at the École in Paris and at the same time professor of physics and chemistry at the Sorbonne. 1809 gemeinsmam awarded him with Louis Jacques Thénard by the mathematical-physical class of the Institut de France, the exposed of Napoleon Bonaparte Galvanic prize of 3000 francs. Gay -Lussac spoke several languages: Italian, English, German. He was a member of many official commissions (eg Comité des arts et consultatif of manufactures (1805 ), Conseil de perfectionnement of poudres et des salpêtres (1818 ) ). He gave out since 1816 together with the Annales de Chimie et Arago de Physique. On 31 May 1842 he was admitted to the Prussian Order Pour le Mérite for Arts and Sciences as a foreign member.
He married the daughter of an impoverished musician.
An explosion with hydrocarbons to Gay -Lussac had contracted a heavy hand suffering. He never overcame this accident.
On May 9, died in 1850 Gay -Lussac in Paris. He was buried at the Père Lachaise Cemetery.
In Paris, a street and a hotel near the Sorbonne are named after him. He is immortalized in particular on the Eiffel Tower, see: The 72 names on the Eiffel Tower.
Theses
Physical chemistry
In 1802 he formulated the so-called law of Gay- Lussac, after the gases expand proportionally with increasing temperature if the pressure remains constant. The coefficient of volume increase, the Gay -Lussac per degree temperature increase certain lag ( actually 1/ 273) at 1/ 266.
Under this law, A. Crawford determined the temperature at which the volume of a gas disappears. These calculations led close up to the absolute zero of temperature ( -273 ° C).
Mental preparation for the Gay -Lussac law, there were already some prominent scientists ( Amontons, Lambert, Charles), who had not yet determined the degree of expansion when the temperature rises sufficiently precise. Jacques Alexandre César Charles already noted, a uniform expansion of gases (oxygen, nitrogen, hydrogen ) in the range of 0-100 ° C.
Gay -Lussac investigated together with Alexander von Humboldt, the volume amounts of hydrogen and oxygen combine to form water. They discovered that just connect two parts by volume of hydrogen gas with a volume of oxygen gas to form water. Furthermore, it made experiments to determine the composition of the air.
Experiments with other gases led him to the conclusion that by the space of atomic gases to form compounds in a simple ratio are ( law of multiple volumes). Under this law, developed a little later Amedeo Avogadro 's hypothesis, Avogadro's law was to later.
The law of multiple volumes led Gay-Lussac to further conclusions. In 1815 Gay -Lussac developed a method for the determination of vapor densities. By means of the vapor molecule density mass determinations were made of organic and inorganic compounds. Only the determination of the volume and weight of a gas resulting from the distillation is sufficient to - determine the actual weight of a readily volatile organic molecule - by comparison with a hydrogen gas. He used this method to determine the molecular weights of hydrogen cyanide, ethanol, diethyl ether.
Later (1865 ) improved this method by August Wilhelm von Hofmann and Victor Meyer.
1807 led Gay -Lussac temperature experiments with two through a tube connected, separable and equal spaces. With an air pump, he evacuated to a room and then let the gas flow from the other room. He put it down a temperature increase during inflow and a decrease in temperature when flowing out of the gas. This experiment was carried out in 1845 by James Prescott Joule with better methods of measurement, its result came as Joule 's law in science, and so laid the foundation for the internal energy of thermodynamics. However, the foundation for the relationship has laid Gay -Lussac.
Gay -Lussac also determined the heat capacity of gases at constant pressure and constant volume. In 1822, he led the universal gas constant R from the ratio Cp - Cv = R a. Regnault was later able to determine the relationship more precisely, therefore R is also called the Regnault constant.
In addition, Gay -Lussac dealt with studies on the diffusion of liquids, with the determination of boiling points of two liquids, with the dependence of solubility and temperature of salts. Gay -Lussac also has tools for physico- chemical work improves (measurement of the vapor pressure, improved barometer, pressure balance ).
Inorganic Chemistry
Since 1808 examined Gay-Lussac and Louis Jacques Thénard the production of pure potassium, sodium, of potassium hydroxide by means of a voltaic pile. Here he contracted a serious eye injury. A year passed before his sight was reasonably sufficient again.
In 1809 Gay -Lussac and Louis Jacques Thénard found the amides of potassium and sodium. In 1810, they found the peroxides of potassium and sodium.
Gay -Lussac investigated the 1811 discovered by Bernard Courtois iodine and showed that the chemical properties of iodine and chlorine are similar. He thereby discovered the hydroiodic acid and potassium iodide. He measured the oxidation of sulfurous acid ( 1813) and of ions of nitrogen. Together with Thénard 1808 he discovered the elemental boron and almost anhydrous hydrofluoric acid.
Gay -Lussac was able to show that the theory of Lavoisier, that all acids contain oxygen, was incorrect. He found that hydrochloric acid gas contains no bound oxygen, hydrogen cyanide and hydrogen sulfide could identify them as acids. Since the known acids always contain hydrogen, led Gay -Lussac a the prefix Hydro.
Organic chemistry
Together with Gay-Lussac Thénard developed an apparatus for organic elemental analysis using potassium chlorate as an oxidant. The volume of the burnt gas was determined in a mercury tube, the carbon dioxide is bound with potassium hydroxide and then determined. From 1815 to replace Gay -Lussac for the elemental analysis, the potassium chlorate by copper ( I) oxide. Upon examination of the hydrocyanic acid that contains nitrogen, he used pure copper for elemental analysis.
Gay-Lussac specific chemical composition of the cyanogen chloride, ethanol and diethyl ether, it also identified, the equation of the fermentation.
Shared with Justus von Liebig Gay -Lussac investigated the silver fulminate. In 1828 Gay-Lussac can chlorine on fats and waxes act, he realized this a replacement of hydrogen by chlorine.
Analytical Chemistry
Gay -Lussac developed a method for the determination of alcohol and a volumetric method for the determination of the silver content. He also introduced the volumetric analysis and titration. Importantly, the Chlorimetrie (1824 ) for the determination of chlorine or silver and alkalimetry (1828 ) were.
Technical Chemistry
For collecting of nitrous gases in sulfuric acid production, he developed the Gay -Lussac tower.
Works
- Recherches physico- chimiques (1811 )