Ammonium alum
{{chembox
| Watchedfields = changed
| verifiedrevid = 442343812
| Name =
| ImageFile =
| ImageFile1 = Ammonium alum crystals.jpg
| ImageSize1 = 300px
| IUPACName =
| OtherNames = {{Unbulleted list|Ammonium alum sulfate|Tschermigite}}
| SystematicName =
| Section1 = {{Chembox Identifiers
| SMILES = [Al+3].[O-]S(=O)(=O)[O-].[O-]S([O-])(=O)=O.[NH4+]
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 7784-25-0
| CASNo1_Ref = {{cascite|correct|CAS}}
| CASNo1 = 7784-26-1
| CASNo1_Comment = (dodecahydrate)
| EINECS = 232-055-3
| KEGG = D02842
| KEGG_Comment = (dodecahydrate)
| RTECS = WS5640010
| PubChem = 3032540
| PubChem1 = 62668
| PubChem1_Comment = (dodecahydrate)
| EC_number_Comment = 616-522-2 (dodecahydrate)
| InChI = 1/Al.H3N.2H2O4S/c;;2*1-5(2,3)4/h;1H3;2*(H2,1,2,3,4)/q+3;;;/p-3
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Al.H3N.2H2O4S/c;;2*1-5(2,3)4/h;1H3;2*(H2,1,2,3,4)/q+3;;;/p-3
| InChIKey = LCQXXBOSCBRNNT-DFZHHIFOAY
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = LCQXXBOSCBRNNT-UHFFFAOYSA-K
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 2297489
| ChemSpiderID1_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID1 = 56419
| ChemSpiderID1_Comment = (dodecahydrate)
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = DPU64XYB1D
| UNII1_Ref = {{fdacite|correct|FDA}}
| UNII1 = 5C36DRL9ZN
| UNII1_Comment = (dodecahydrate)
}}
| Section2 = {{Chembox Properties
| Properties_ref = {{RubberBible62nd|pages=B-74, B-75}}.
| Formula = (NH4)Al(SO4)2
| MolarMass = 237.15 g/mol (anhydrous)
453.33 g/mol (dodecahydrate)
| Appearance = white crystals
| Density = 2.45 g/cm3 (anhydrous)
1.64 g/cm3 (dodecahydrate)
| MeltingPtC = 93.5
| MeltingPt_notes = (dodecahydrate)
| BoilingPtC = 120
| BoilingPt_notes = dehydr. (dodecahydrate)
| Solubility = 15 g/100 ml (20 °C, dodecahydrate)
}}
| Section3 = {{Chembox Structure
| CrystalStruct = Hexagonal (anhydrous)
Cubic (dodecahydrate)
| SpaceGroup =
| Coordination = Octahedral (Al3+)
| LattConst_a =
}}
| Section4 =
| Section5 =
| Section6 =
| Section7 = {{Chembox Hazards
| Hazards_ref = {{GHS class NZ|id=15938|access-date=2009-11-23}}.
| GHSPictograms = {{GHS07|Skin Irrit. 2; Eye Irrit. 2}}
| GHSSignalWord = WARNING
| HPhrases = {{H-phrases|315|319}}
| PPhrases = {{P-phrases|264|280|302+352|305+351+338|321|332+313|337+313|362}}
| FlashPt = Non-flammable
| ExternalSDS = [http://hazard.com/msds/mf/baker/baker/files/a2760.htm External MSDS]
}}
}}
Ammonium aluminium sulfate, also known as ammonium alum or just alum (though there are many different substances also called "alum"), is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH4)Al(SO4)2·12H2O. It is used in small amounts in a variety of niche applications. The dodecahydrate occurs naturally as the rare mineral tschermigite.
Production and basic properties
Ammonium alum is made from aluminium hydroxide, sulfuric acid and ammonium sulfate. It forms a solid solution with potassium alum. Pyrolysis leaves alumina. Such alumina is used in the production of grinding powders and as precursors to synthetic gems.Otto Helmboldt, L. Keith Hudson, Chanakya Misra, Karl Wefers, Wolfgang Heck, Hans Stark, Max Danner, Norbert Rösch "Aluminum Compounds, Inorganic" in Ullmann's Encyclopedia of Industrial Chemistry 2007, Wiley-VCH, Weinheim.{{doi|10.1002/14356007.a01_527.pub2}}
Uses
Ammonium alum is not a major industrial chemical or a particularly useful laboratory reagent, but it is cheap and effective, which invites many niche applications. It is used in water purification, in vegetable glues, in porcelain cements, in deodorants and in tanning, dyeing and in fireproofing textiles.{{citation | url = https://www.questia.com/library/encyclopedia/alum.jsp | contribution = Alum | title = The Columbia Encyclopedia | year = 2004 | edition = 6th | publisher = Columbia University Press | location = Ithaca, NY | access-date = 2009-11-23 | archive-date = 2009-10-17 | archive-url = https://web.archive.org/web/20091017095045/http://www.questia.com/library/encyclopedia/alum.jsp | url-status = dead }}. The pH of the solution resulting from the topical application of ammonium alum with perspiration is typically in the slightly acid range, from 3 to 5.{{citation | url = http://hazard.com/msds/mf/baker/baker/files/a2760.htm | title = Aluminum Ammonium Sulfate Material Safety Data Sheet | publisher = J. T. Baker | date = March 2009 | access-date = 2009-11-23}}.
Ammonium alum is a common ingredient in animal repellent sprays.{{citation | url = http://www.bruceharris.com.au/BHPMweb/dter_faq.htm | title = D-TER Animal and Bird Repellent | publisher = Bruce Harris Project Management Pty Ltd | date = 2004-09-04 | access-date = 2010-03-03 | archive-date = 2009-10-15 | archive-url = https://web.archive.org/web/20091015031644/http://bruceharris.com.au/BHPMweb/dter_faq.htm | url-status = dead }}.{{citation | url = http://www.multicrop.com.au/pdfs/MULTICROP-SCAT-BIRD-AND-ANIMAL-REPELLENT-Ref-%281226%29.pdf | title = Multicrop Scat Bird and Animal Repellent Data Sheet | publisher = Multicrop (Aust.) Pty. Ltd. | date = 2003-03-04 | access-date = 2010-03-03}}.{{citation | url = http://www.tandridge.gov.uk/environment/pestcontrol/foxes.htm | title = Pest Control: Foxes | publisher = Tandridge District Council (UK) | date = February 2006 | access-date = 2010-03-03}}.
References
{{reflist}}
{{Aluminium compounds}}
{{Ammonium salts}}
{{DEFAULTSORT:Ammonium Aluminium Sulfate}}