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Magnesium perchlorate

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This is an old revision of this page, as edited by Synthesium (talk | contribs) at 10:27, 12 August 2016 (Important information: this product decomposes in 250 deg. C so drying must be provided in lower temperatures). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Magnesium perchlorate
Magnesium perchlorate
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.030.086 Edit this at Wikidata
RTECS number
  • SC8925000
UNII
  • InChI=1S/2ClHO4.Mg/c2*2-1(3,4)5;/h2*(H,2,3,4,5);/q;;+2/p-2 checkY
    Key: MPCRDALPQLDDFX-UHFFFAOYSA-L checkY
  • InChI=1/2ClHO4.Mg/c2*2-1(3,4)5;/h2*(H,2,3,4,5);/q;;+2/p-2
    Key: MPCRDALPQLDDFX-NUQVWONBAH
  • [Mg+2].O=Cl(=O)(=O)[O-].[O-]Cl(=O)(=O)=O
Properties
Mg(ClO4)2
Molar mass 223.206 g/mol
Appearance white powder,
deliquescent
Odor odorless
Density 2.21 g/cm3 (anhydrous)
1.98 g/cm3 (hexahydrate)
Melting point 251 °C (484 °F; 524 K) (anhydrous)
95-100 °C (hexahydrate)
Boiling point decomposition
99.3 g/100 mL
Solubility in ethanol 23.96 g/100 mL
Hazards
NFPA 704 (fire diamond)
Safety data sheet (SDS) External MSDS
Related compounds
Other cations
Calcium perchlorate
Barium perchlorate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Magnesium perchlorate is a powerful oxidizing agent, with the formula Mg(ClO4)2. It is also a superior drying agent for gas analysis.

Magnesium perchlorate decomposes at 250 °C.[1] The heat of formation is -568.90 kJ mol−1.[2]

The enthalpy of solution is quite high, so reactions are done in large amounts of water to dilute it.

It is sold under the trade name anhydrone. Manufacture of this product on a semi-industrial scale was first performed by G. Frederick Smith Ph.D. in his garage in Urbana Illinois, but later at a permanent facility in Columbus, OH called G. Frederick Smith Chemical Co. He sold the magnesium perchlorate to A. H. Thomas Co., now Thomas Scientific, under the trade name Dehydrite.

It is used as desiccant to dry gas or air samples,[3][4] but is no longer advised, for use as a general desiccant, due to hazards inherent in perchlorates.[5] It is dried by heating at 220 °C under vacuum.

Magnesium perchlorate is created by the reaction of magnesium hydroxide and perchloric acid.

References

  1. ^ CRC Handbook
  2. ^ Lange's
  3. ^ H. H. Willard, G. F. Smith (1922). "The Preparation and Properties of Magnesium Perchlorate and its Use as a Drying Agent". Journal of the American Chemical Society. 44 (10): 2255–2259. doi:10.1021/ja01431a022.
  4. ^ L. Wu, H. He (1994). "Preparation of perlite-based magnesium perchlorate desiccant with colour indicator". The Chemical Educator. 41 (5): 633–637. doi:10.1016/0039-9140(94)80041-3.
  5. ^ W. L. F. Armarego and C. Chai (2003). Purification of laboratory chemicals. Oxford: Butterworth-Heinemann. ISBN 0-7506-7571-3.