Ammonium aluminium sulfate

Ammonium aluminium sulfate dodecahydrate IUPAC name Aluminium ammonium bis(sulfate) – water (1:12) Other names Ammonium alum Tschernigite Identifiers InChI InChI=1/Al.H3N.2H2O4S.12H2O/c;;2*1-5(2,3)4;;;;;;;;;;;;/h;1H3;2*(H​2,1,2,3,4);12*1H2/q+3;;;;;;;;;;;;;;;/p-3 InChIKey WZUKKIPWIPZMAS-DFZHHIFOAD Standard InChI InChI=1S/Al.H3N.2H2O4S.12H2O/c;;2*1-5(2,3)4;;;;;;;;;;;;/h;1H3;2*(​H2,1,2,3,4);12*1H2/q+3;;;;;;;;;;;;;;;/p-3 Standard InChIKey WZUKKIPWIPZMAS-UHFFFAOYSA-K CAS number [7784-26-1] EC number 232-055-3 RTECS WS5640010 ChemSpider 56419 Properties Chemical formula (NH4)Al(SO4)2·12H2O Molar mass 453.33 g/mol Appearance white crystals Density 1.64 g/cm3 Melting point 93.5 °C Boiling point 120 °C dehydr. Solubility in water 15 g/100 ml (20 °C) Structure Crystal structure Cubic Coordination geometry Octahedral (Al3+) Hazards Material safety data sheet (MSDS) External MSDS EU index number not listed Flash point non-flammable Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Ammonium aluminium sulfate IUPAC name Aluminium ammonium bis(sulfate) Other names Ammonium alum Identifiers InChI InChI=1/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 Standard InChI InChI=1S/Al.H3N.2H2O4S/c;;2*1-5(2,3)4/h;1H3;2*(H2,1,2,3,4)/q+3;;;​/p-3 Standard InChIKey LCQXXBOSCBRNNT-UHFFFAOYSA-K CAS number [7784-25-0] EC number 232-055-3 RTECS WS5640010 ChemSpider 2297489 Properties Chemical formula (NH4)Al(SO4)2 Molar mass 237.15 g/mol Appearance white crystals Density 2.45 g/cm3 Solubility in water soluble Structure Crystal structure Hexagonal Coordination geometry Octahedral (Al3+) Hazards EU index number not listed Flash point non-flammable Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Ammonium aluminium sulfate, also known as ammonium alum is a white crystalline double sulfate usually encountered as the dodecahydrate, formula (NH₄)Al(SO₄)₂·12H₂O. It is used in water purification, in vegetable glues, in porcelain cements, in natural deodorants and in tanning, dyeing and in fireproofing textiles. The dodecahydrate occurs naturally as the rare mineral tschernigite.

No human or ecological (for reduced concentrations) toxicity registered.

Uses

The pH of the solution resulting from the topical application of ammonium alum with perspiration is typically in the slightly acid range, from 4 to 5. It is a popular deodorant. A 120 gram stone lasts for at least a year of daily usage -- much longer than other deodorants and antiperspirants. It is also hypoallergenic and non-staining. Potassium alum is also used for this purpose.