Aluminium compounds: dialuminium trisulphate octadecahydrate

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The aluminium in dialuminium trisulphate octadecahydrate formally is in the oxidation state 3.

Dialuminium trisulphate octadecahydrate

  • Formula as often written: Al2(SO4)3.18H2O
  • Hill system formula: Al2H36O30S3
  • CAS registry number: [7784-31-8]
  • Formula weight: 666.429
  • Class: complex


  • dialuminium trisulphate octadecahydrate
  • aluminium(III) sulphate 18-water
  • aluminium sulfate 18-water
  • aluminium sulphate 18-water
  • aluminium(III) sulfate 18-water
  • aluminum sulfate 18-water
  • aluminum sulphate 18-water
  • aluminum(III) sulfate 18-water
  • aluminum(III) sulphate 18-water
  • dialuminium trisulfate octadecahydrate
  • dialuminum trisulfate octadecahydrate
  • dialuminum trisulphate octadecahydrate

Physical properties

  • Colour: white
  • Appearance: crystalline solid
  • Melting point: 87°C (decomposes)
  • Boiling point:
  • Density: 1690 kg m-3


Coming soon...

Element analysis

Element percentages for the elements in dialuminium trisulphate octadecahydrate
Element %
Al 8.10
H 5.44
O 72.02
S 14.43


Not available

Isotope pattern

What follows is the calculated isotope pattern for the Al2(SO4)3.18H2O unit with the most intense ion set to 100%.

Formula: Al2S3O30H36

mass  %
666 100.0 __________________________________________________
667 3.9 __
668 19.3 __________
669 0.7
670 1.6 _
671 0.0
672 0.1


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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