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Magnesium chloride

From Simple English Wikipedia, the free encyclopedia

Magnesium chloride is a chemical compound made of magnesium and chlorine. It has the chemical formula MgCl2. It is the main ingredient used to make magnesium metal.

It is hygroscopic, meaning it attracts water to form hydrates easily.

Preparation

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Hydrated magnesium chloride is mostly made from brine. The anhydrous (water-free) salt cannot be made by heating the hydrate because it will decompose into hydrogen chloride and magnesium hydroxychlorides.[1] Instead, the water-free salt is made by heating ammonia complexes.[2]

Electrolysis of molten magnesium chloride is the main way people make elemental magnesium metal. This also makes chlorine gas.[source?] Magnesium chloride can also be reduced by strong reducing agents like potassium.[3]

  1. Huang, Qiongzhu; Lu, Guimin; Wang, Jin; Yu, Jianguo (2011). "Thermal decomposition mechanisms of MgCl2·6H2O and MgCl2·H2O". Journal of Analytical and Applied Pyrolysis. 91: 159–164. doi:10.1016/j.jaap.2011.02.005.
  2. Eom, Hyoung-Choon; Park, Hyungkyu; Yoon, Ho-Sung (2010). "Preparation of anhydrous magnesium chloride from ammonium magnesium chloride hexahydrate". Advanced Powder Technology. 21 (2): 125–130. doi:10.1016/j.apt.2010.01.003.
  3. Rieke, Reuben D.; Li, Percy Tzu-Jung; Burns, Timothy P.; Uhm, Sung T. (1981). "Preparation of highly reactive metal powders. New procedure for the preparation of highly reactive zinc and magnesium metal powders". The Journal of Organic Chemistry. 46 (21): 4323–4324. doi:10.1021/jo00334a056.