Aluminum potassium sulfate dodecahydrate
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| General | ||||||||||||||||
| Surname | Aluminum potassium sulfate dodecahydrate | |||||||||||||||
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| Molecular formula | KAl (SO 4 ) 2 • 12 H 2 O | |||||||||||||||
| Brief description |
colorless octahedral crystals |
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| properties | ||||||||||||||||
| Molar mass | 474.39 g mol −1 | |||||||||||||||
| Physical state |
firmly |
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| density |
1.75 g cm −3 |
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| Melting point |
92.5 ° C |
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| boiling point |
not available (release of water of crystallization 60–200 ° C, decomposition 780 ° C (anhydrous)) |
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| solubility |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||||||||
Aluminum potassium sulfate dodecahydrate , also known as potassium aluminum sulfate dodecahydrate, potassium alum, potash alum or alum , forms colorless octahedral crystals.
properties
The solubility of aluminum potassium sulfate increases sharply with temperature. Large octahedral crystals can be grown from hot, saturated solution.
use
It used to be important in tannery and dyeing, but has now been replaced by aluminum sulfate .
Even today it is sometimes used as a " razor stone " to stop bleeding. Due to its odor-inhibiting effect, it is contained in some deodorants. It acts as an inhibitor in the breakdown of sweat into butyric acid.
It is added to food as a firming agent or stabilizer . In the EU it is approved as a food additive with the designation E 522 only for egg white and glazed, candied or crystallized fruit and vegetables.
It is used under the trade name LMA as a pesticide against fire blight ; in Germany, however, it can only be used to a very limited extent due to an emergency approval.
It is colored with food coloring and offered in hobby crystal growing experiment boxes.
An anhydrous potassium aluminum sulfate, KAl (SO 4 ) 2, is also known.
Aluminum potassium sulfate has been used as an adjuvant in diphtheria vaccines or diphtheria combination vaccines since the mid-1920s ("Alum"). It is considered to be the first adjuvant used in human vaccines. Originally, water-soluble AlK (SO 4 ) 2 was mixed directly with antigen dissolved in a phosphate buffer ( precipitation ). The precipitate is amorphous aluminum potassium sulfate and has similar properties to the adjuvant aluminum phosphate.
Individual evidence
- ↑ a b entry on alum. In: Römpp Online . Georg Thieme Verlag, accessed on July 15, 2014.
- ↑ a b External identifiers of or database links for aluminum potassium sulfate anhydrate : CAS number: 10043-67-1, EC number: 233-141-3, ECHA InfoCard: 100.030.116 , GESTIS substance database : 5000 , PubChem : 24856 , DrugBank : DB09087 , Wikidata : Q411309 .
- ↑ a b c d e f Data sheet aluminum potassium sulfate dodecahydrate (PDF) from Merck , accessed on June 3, 2018.
- ↑ ZZulV : Appendix 4 (to Section 5, Paragraph 1 and Section 7) Limited additives
- ↑ LMA against fire blight in pome fruit, product information from the manufacturer , technical information for Switzerland, as of March 2019, user information for the authorization in Switzerland, which is limited to 2016
- ↑ Emergency approval according to Art. 53 of Regulation (EC) No. 1107/2009, approval 2019 of 260t for the period from April 1 to July 29, 2019
- ^ DV West, Q. Huang, HW Zandbergen, TM McQueen, RJ Cava: Structural disorder, octahedral coordination and two-dimensional ferromagnetism in anhydrous alums. In: Journal of Solid State Chemistry . 181, No. 10, 2008, pp. 2768-2775, doi: 10.1016 / j.jssc.2008.07.006 .
- ↑ a b Stanley A. Plotkin et al .: Plotkin's Vaccines . 7th edition. Elsevier, Philadelphia 2017, ISBN 978-0-323-35761-6 , pp. 64 ( elsevier.com ).
- ↑ Armando A Paneque-Quevedo: Inorganic compounds as vaccine adjuvants . Ed .: Biotecnología Aplicada. tape 30 , no. 4 , 2013, ISSN 1027-2852 , p. 250–256 (English, sld.cu ).