Stanislao Cannizzaro (Cannizzaro Stanislao)( Italian chemist.)
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Biography Stanislao Cannizzaro (Cannizzaro Stanislao)
Born July 13, 1826 in Palermo (Sicily). He studied medicine at the universities of Palermo and Pisa. In 1845-1847 he worked at the Italian chemist R. Piria in Pisa, in parallel attended lectures on chemistry, helped Piria in his studies. In 1847 he returned to Palermo, participated in the revolt against the Bourbons, after its suppression in 1849 went to France, worked in the laboratory of M. Chevrel, opened with F. Kloezom cyanamide, and studied its thermal ionization. In 1851 received an invitation to take the chair of chemistry, physics and mechanics at the National College in Alessandria, was a professor at the University of Genoa (1856-1861), Palermo (1861-1871) and Rome (1871-1910).
In 1852, studying the effects of potassium hydroxide on benzaldehyde, discovered the reaction in which benzyl alcohol was obtained at the same time opened the oxidation of one molecule of aldehyde due to restoration of the other in alkaline medium (Cannizzaro reaction). In 1858 Cannizzaro wrote a pamphlet A Brief Outline of the philosophy of chemistry (Sunto di un corso di filosopfia chimica), which actively supported the hypothesis formulated in 1811 by A. Avogadro. According to this hypothesis, equal volumes of gases at the same temperature and pressure contain the same number of molecules. Many scholars have treated this revolutionary idea is very skeptical, . later disputes have become so loud, . that for their permission in 1860 in Karlsruhe, was convened by the International Congress of Chemists, . which took place on a hot discussion with KekulцL von Stradonitz, . Dumas, . Wurtz and other scientists,
. Cannizzaro circulated to present their brochure, which insisted on strict separation between such fundamental concepts as atoms, the equivalent of a molecule, valence, and the need to adopt new teaching. In 1858 Cannizzaro has developed a reliable method of determining the atomic weights of elements by their percentage in the pure compounds and suggested a rational system of atomic masses. In 1891 the Royal Society awarded the Copley Medal Cannizzaro.
In 1871 Cannizzaro was elected to the Senate, and later became vice-president. As a member of the Board of Education was in charge of science education in Italy. Cannizzaro died in Rome on May 10, 1910.