Magnesium perchlorate

Magnesium perchlorate

Identifiers
CAS Number	10034-81-8
3D model (Jmol)	Interactive image
ChemSpider	23223
ECHA InfoCard	100.030.086
PubChem	24840
RTECS number	SC8925000
UNII	7N77Z541YF
InChI InChI=1S/2ClHO4.Mg/c2*2-1(3,4)5;/h2*(H,2,3,4,5);/q;;+2/p-2 Key: MPCRDALPQLDDFX-UHFFFAOYSA-L InChI=1/2ClHO4.Mg/c2*2-1(3,4)5;/h2*(H,2,3,4,5);/q;;+2/p-2 Key: MPCRDALPQLDDFX-NUQVWONBAH
SMILES [Mg+2].O=Cl(=O)(=O)[O-].[O-]Cl(=O)(=O)=O
Properties
Chemical formula	Mg(ClO4)2
Molar mass	223.206 g/mol
Appearance	white powder, deliquescent
Odor	odorless
Density	2.21 g/cm^3 (anhydrous) 1.98 g/cm^3 (hexahydrate)
Melting point	251 °C (484 °F; 524 K) (anhydrous) 95-100 °C (hexahydrate)
Boiling point	decomposition
Solubility in water	99.3 g/100 mL
Solubility in ethanol	23.96 g/100 mL
Hazards
Safety data sheet	External MSDS
R-phrases	R8, R36, R37, R38
S-phrases	S17, S26, S27, S36, S37, S39
NFPA 704	0 1 0 OX
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).
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Infobox references

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.

Salts and the ester of the perchlorate ion
HClO4																	He
LiClO4	Be(ClO4)2											B(ClO4)4^−	ROClO3	N(ClO4)3 NH4ClO4	O	FClO4	Ne
NaClO4	Mg(ClO4)2											Al(ClO4)3	Si	P	S	ClO4^− ClOClO3 Cl2O7	Ar
KClO4	Ca(ClO4)2	Sc(ClO4)3	Ti(ClO4)4	VO(ClO4)3	Cr(ClO4)3	Mn(ClO4)2	Fe(ClO4)3	Co(ClO4)2, Co(ClO4)3	Ni(ClO4)2	Cu(ClO4)2	Zn(ClO4)2	Ga(ClO4)3	Ge	As	Se	Br	Kr
RbClO4	Sr(ClO4)2	Y	Zr	Nb	Mo	Tc	Ru	Rh	Pd(ClO4)2	AgClO4	Cd(ClO4)2	In	Sn	Sb	Te	I	Xe
CsClO4	Ba(ClO4)2		Hf	Ta	W	Re	Os	Ir	Pt	Au	Hg2(ClO4)2, Hg(ClO4)2	Tl(ClO4)3	Pb(ClO4)2	Bi(ClO4)3	Po	At	Rn
Fr	Ra		Rf	Db	Sg	Bh	Hs	Mt	Ds	Rg	Cn	Nh	Fl	Mc	Lv	Ts	Og
		↓
		La	Ce(ClO4)x	Pr	Nd	Pm	Sm	Eu	Gd	Tb	Dy	Ho	Er	Tm	Yb	Lu
		Ac	Th	Pa	UO2(ClO4)2	Np	Pu	Am	Cm	Bk	Cf	Es	Fm	Md	No	Lr