Mercury (I) chloride
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| General | ||||||||||
| Surname | Mercury (I) chloride | |||||||||
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| Molecular formula | Hg 2 Cl 2 | |||||||||
| Brief description |
colorless odorless crystals |
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| properties | ||||||||||
| Molar mass | 472.09 g mol −1 | |||||||||
| Physical state |
firmly |
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| density |
7.15 g cm −3 |
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| Sublimation point |
400 ° C |
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| Vapor pressure |
0.3 m Pa (50 ° C) |
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| solubility |
very bad in water (2.3 mg l −1 at 20 ° C) |
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| safety instructions | ||||||||||
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| MAK |
0.1 mg m −3 |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||
Mercury (I) chloride ( calomel , from ancient Greek καλός kalos 'beautiful' and μέλας melas 'black', meaning 'beautiful black'; in the past also sweet mercury , mercury chloride or mercury horn ore ) is a colorless solid that only differs in water slightly soluble and at about 380 ° C sublimates . The empirical formula is Hg 2 Cl 2 .
In the light it gradually turns dark to black (hence the name calomel) because it disproportionates and disintegrates into elemental mercury and mercury (II) chloride .
Occurrence
Mercury (I) chloride occurs naturally as the rare mineral calomel , a dark gray mineral that can be gray-yellow to light yellow with higher levels of mercury (I) chloride. Very small, pure mercury (I) chloride crystals are found even more rarely in drusen .
use
Mercury (I) chloride is used in calomel electrodes for potentiometry , for pest control, in pyrotechnics for green glowing torches, in porcelain painting for applying gold and as a catalyst.
medicine
As it is hardly absorbed by the body due to its extremely low water solubility, it has been used in many different ways in medicine (as calomel, also calomel): against inflammation in the nose and throat, as a laxative, to stimulate the biliary function, against diarrhea, dropsy, spleen -, liver and lung diseases and against syphilis , as well as externally against corneal spots, chickenpox, ulcers, and genital warts.
It was also used as a spermicide in chemical contraceptives until the 1990s .
Individual evidence
- ↑ a b c d e f data sheet mercury (I) chloride from AlfaAesar, accessed on February 9, 2010 ( PDF )(JavaScript required) .
- ↑ a b Data sheet mercury (I) chloride (PDF) from Merck , accessed on February 9, 2010.
- ↑ a b Entry on mercury (I) chloride in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .
- ↑ Entry on Dimercury dichloride in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
- ↑ Emil Stern: About the mercury chloride-chlorosodium and its subcutaneous use. In: Berlin clinical weekly. Volume 15, 1878, pp. 59-64.
literature
- AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 91st – 100th, improved and greatly expanded edition. Walter de Gruyter, Berlin 1985, ISBN 3-11-007511-3 , p. 1046.
- Fachlexikon ABC Chemie, Volume 2, 3rd edition, Harri Deutsch Frankfurt 1987, p. 957, ISBN 3-87144-899-0 .
- JG Krünitz: Economic Encyclopedia . Berlin: Pauli, pp. 1773-1858.