Scheele. Karl

Molybdenum was first identified as a distinct element by Swedish chemist Karl Wilhelm Scheele in 1778. The metal was isolated by Hjelm in 1782 by reduction of its oxide with carbon. Moissan in 1895 isolated the metal in highly purified form by electrolytic reduction of its oxide and studied many of its physical and chemical properties. The element derived its name in 1816 from the word molybdos, meaning a soft mineral that appeared like lead. 

The other half-metal referred to in the preceding letter was hydro-siderum, a false element which Apothecary Johann Karl Friedrich Meyer of Stettin, Scheele, and M. H. Klaproth later proved to be a phosphate of iron (73, 74, 41). In another of his letters to Hjelm Scheele said, As far as I can judge of your work, it does you all credit (9). Although this correspondence shows that Hjelm must have isolated molybdenum as early as the fall of 1781, his first paper on it was not published until much later. 

For thousands of years, people have known that no human being can live without air. But it was not until Karl Scheele, a Swedish chemist, in 1772, and Joseph Priestley, an Englishman, in 1774, discovered and described oxygen that people knew that it is the oxygen in the air that is important to life. 

Oxygen was first isolated and characterized in the period 1771-1774 by the English chemist Joseph Priestley and the Swedish chemist Karl Wilhelm Scheele. Priestley and Scheele found that heating certain compounds such as mercury(II) oxide generates a colorless, odorless, tasteless gas that supports combustion better than air does ... 

In one sense, the story of the chlorinated insecticides begins in 1774, since in that year the Swedish apothecary Karl Wilhelm Scheele discovered chlorine Michael Faraday, who was born in 1791 first assisted Sir Humphry Davy and later succeeded him as Professor of Chemistry at the Royal Institution in London In the Philosophical Transactions of 1825 Faraday reported that benzene reacted with chlorine in sunlight to give a "solid body" and dense, viscous fluid, which was undoubtedly the first sample of technical BHC. During the next 87 years several investigations established its constitution to be C/.H/.C1, and showed that it contained a- and 3-isomers and afforded trichlorobenzenes when treated with alkali In 1912, the Belgian chemist Van der Linden... 

Its asphyxiating properties have been recognised ever since it was discovered in 1774 by Karl Wilhelm Scheele. 

Karl Wilhelm Scheele is virtually the only exception. 

A number of others were doing similar work at the same time, notably Cavendish, Joseph Priestley and Karl Scheele. But Rutherford was first to describe nitrogen accurately. 

Latin name of Geber. Geber described a substance with all the properties that we equate with citric acid today, but he knew nothing about its chemical structure. The first person to isolate the compound as a pure substance was the Swedish chemist Karl Wilhelm Scheele (1742-1786), who obtained citric acid from the juice of lemons. By the mid-nineteenth century, citric acid was being produced commercially in Italy from lemons and other citrus fruits. 

Lactic acid was first discovered in 1780 by the Swedish chemist Karl Wilhelm Scheele (1742-1786), who called his discovery acid of milk. The two isomeric forms of the acid were first identified in 1863 by the German chemist Johannes Wisli-cenus (1835-1902), and the compound was first produced commercially in 1881 by American chemist Charles E. Avery. Avery patented his invention in 1885 and constructed a factory for the production of lactic acid in Littleton, Massachusetts. 

Phosphoric acid was discovered independently as a component of bone ash in 1770 by two Swedish chemists, Johann Gottlieb Gahn (1745-1818) and Karl Wilhelm Scheele (1742-1786). Four years later, Scheele discovered that the acid could be made by adding nitric acid to phosphorus. 

In 1777, Karl Wilhelm Scheele (1742-1786) (Fig. 3.16) published the first comprehensive book on the chemical effects of light. Considered the father of... 

Figure 3.16 Statue of Karl Wilhem Scheele (1742-1786), who is considered to be the founder of the science of photochemistry. (Published with permission from the Deutsches Museum, Munich.)...

Oxygen gas was actually first observed by the Swedish chemist Karl W. Scheele (1742-1786), but because his results were published after Priestley s, the latter is commonly credited with the discovery of oxygen. 

Oxygen can be prepared in small quantities by decomposing certain oxygen-containing compounds. Both the Swedish chemist Karl Wilhehn Scheele and the British chemist Joseph Priestley are credited with the discovery of oxygen. Priestley obtained the gas in 1774 by heating mercury(II) oxide. 

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