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(Göttingen, Germany, 1811 - Heidelberg, ID., 1899) German chemist. He studied in his hometown and then completed his studies of chemistry in Paris, Berlin and Vienna, until in 1833, he was called to the University of Göttingen to succeed Friedrich Wöhler at the Department of chemistry. Subsequently he taught at Marburg (1841), in Breslau (1851) and, finally, in Heidelberg (since 1852), where he founded a famous school of chemical and quimico-fisicos.
Especially their activity devoted to problems of physical chemistry, and the discoveries made in this branch made him famous. In the field of organic chemistry highlights its studies of the cacodilo series (1837-1842), result of his work on compounds of cacodilo that allowed to delve into the concept of radical and that allegiance chemistry of organometallic compounds. In the field of inorganic and analytical chemistry is the invention of the battery that bears his surname and his method of separation of metals (magnesium, aluminium, sodium, barium, calcium and lithium) by electrodeposition.
Robert Bunsen presented these findings in each celebrity memories on batteries (1841). They described a stack in which an electrode is formed of a mixture of oil and coke; with this contribution, he managed to equal the value of the electromotive force of battery who had invented the British physicist William Robert Grove. In the same work out Bunsen trials for him with chromic acid and potash bichromate, which gave rise to the most simple type of Bunsen battery.
With some changes made by other scholars, today the Bunsen cell is formed by water acidulated with sulfuric acid (to 10 per cent by weight approximately), which is inmergen a sheet of amalgamated zinc and a prism of charcoal retort which acts as a positive electrode. This Prism is contained in a vessel of clay porous and immersed in nitric acid. The hydrogen that is directed toward retort carbon flows through the porous glass; but rather than settle in the same carbon, giving rise to polarization and thus a decrease in the intensity of the current, reacts with nitric acid, breaking down it, and thus is ensured the consistency of the stack. With the latest improvements, Bunsen battery reaches an electromotive force of close to two volts, while its internal resistance is approaching 0.2 ohms.
Then dedicated to the study of the chemistry and physics of gases, Robert Bunsen invented a number of methods that would expose the work methods gasometrics (1857). Practical outcome of these investigations was the construction, in 1850, the burner or burner Bunsen, still used today in chemical laboratories. Because of the mixture of air and fuel gas prior to ignition, gets a dark flame of high calorific and perfect combustion: the completion of the driving narrows so that there is an air intake, since the pressure in the narrowing is less.
But his greatest discovery is the method of spectral analysis, Robert Bunsen invented together with Gustav Kirchhoff, and that was demonstrated in the next decades as one of the most powerful and fertile methods in the field of physics, Atomic Physics and astronomy. In 1857 he had observed that, by putting a substance over the flame of a Bunsen burner, different colorations depending on the nature of the same occurred. Three years later, Bunsen and Kirchhoff designed and built the first spectroscope, instrument very useful in qualitative chemical analysis that allows to study the spectra of incandescent substances. The light that you want to analyze is placed before an adjustable slit; passing through it, a Prism and a lens system, gets the image of the slit in an eyepiece. He is usually added to the apparatus a micrometer, which is a tube with an illuminated scale.
The same Bunsen discovered, by means of spectral analysis, two new chemical elements, which respectively called cesium and rubidium. Together with Kirchhoff, presented the theory of spectral analysis in a volume published in 1861, by means of spectral observations chemical analysis. In 1864 he took part in a scientific expedition to Iceland, during which he studied volcanic phenomena.