At standard temperature it reacts with mineral acids. Cobalt does not react with hydrogen and nitrogen gas even at high temperatures. It reacts with halogens and produce halides. Cobalt is weak reducing metal and protected from oxidation by formation of a passivating oxide film. Cobalt does not catch fire in air and is resistant to burning, unless it is in powder form. It combines with oxygen and produce Co 3O 4 and lose oxygen at higher temperature (900 oC) and give monoxide (CoO). It is stable in air and is unaffected by water. Chemical CharacteristicsĬobalt is not very reactive metal. It melts at 1495 oC and its boiling temperature is 2927 oC. Pure cobalt is obtained through smelting process, which is hard and lustrous and release vapors of arsenic. Cobalt is a ferromagnetic (strongest magnet), up to 1121 0C. Its physical properties resemble iron and nickel. Refined or polished cobalt is a silvery white metal and have a faint bluish tinge. Large deposits of cobalt are present in Canada, Australia, Zambia and Brazil. Cobalt is produced as a byproduct during the mining and refining nickel, silver, lead, copper and iron. Most common minerals of cobalt are cobaltite (cobalt sulfoarsenide mineral), linnaeite (sulfide mineral), skutterudite (series of cobalt and nickel mineral), and smaltite (cobalt, nickel arsenide). In compound form, it occurs in minerals of in copper and nickel. Cobalt is mostly present in combination with nickel. It is present in the sun, in soil, and in bodies of plants and animals. It is the 32 nd most abundant element present on the earth crust. Cobalt Periodic Table ClassificationĬobalt is widely present on the earth crust, in combination with other minerals and in natural water. The word kobold derived from German word meaning ‘’goblin ore’’. Brandt in 1742 determined that in various ores, the blue color is due to the presence of cobalt. In 16 th century kobold name was given to the ores that contain copper but in the end found that ores contain poisonous arsenic. Cobalt in the form of metal was isolated by George Brandt in 1735. It was also used in China for pottery glazes as early as 618-907 CE. It has been found in Egyptian statuettes and in Persian jewelry of the 3 rd millennium BCE. History and DiscoveryĬobalt has been used as a coloring agent since Bronze Age. Its compounds are known as cobalt blue used to color pottery and glass. Cobalt is transition metal and was discovered in pure form in 1735.
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