Magnesium chlorate

Magnesium chlorate
Names
	IUPAC name Magnesium dichlorate hexahydrate
	Systematic IUPAC name Magnesium dichlorate
	Other names Magnesium(II) chlorate;
Identifiers
CAS Number	10326-21-3; (dihydrate): 36355-97-2; (hexahydrate): 7791-19-7;
3D model (JSmol)	Interactive image; (dihydrate): Interactive image; (hexahydrate): Interactive image;
ChemSpider	64853748; (dihydrate): 80564724; (hexahydrate): 128878;
ECHA InfoCard	100.030.634
EC Number	233-711-1;
PubChem CID	25155; (dihydrate): 71437298; (hexahydrate): 146100;
UNII	M536P01U3N;
UN number	2723
CompTox Dashboard (EPA)	DTXSID30890653 ; (hexahydrate): DTXSID30999110;
	InChI InChI=1S/2ClHO3.Mg/c22-1(3)4;/h2(H,2,3,4);/q;;+2/p-2 Key: NNNSKJSUQWKSAM-UHFFFAOYSA-L; (dihydrate): InChI=1S/2ClHO3.Mg.2H2O/c22-1(3)4;;;/h2(H,2,3,4);;21H2/q;;+2;;/p-2 Key: YTXOASNCVSJHNM-UHFFFAOYSA-L; (hexahydrate): InChI=1S/2ClHO3.Mg.6H2O/c22-1(3)4;;;;;;;/h2(H,2,3,4);;61H2/q;;+2;;;;;;/p-2 Key: XKPLAISKKLSAQQ-UHFFFAOYSA-L;
	SMILES Cl(=O)(=O)[O-].Cl(=O)(=O)[O-].[Mg+2]; (dihydrate): O.O.[Mg+2].[O-]Cl(=O)=O.[O-]Cl(=O)=O; (hexahydrate): O.O.O.O.O.O.[O-]Cl(=O)=O.[O-]Cl(=O)=O.[Mg+2];
Properties
Chemical formula	Mg(ClO3)2
Molar mass	191.20 g/mol
Appearance	White crystalline solid
Density	1.747 g/cm3 (hexahydrate)
Melting point	35 °C (95 °F; 308 K)
Boiling point	120 °C (248 °F; 393 K) (decomposition)
Solubility in water	114 g/100 ml (0 °C); 123 g/100 ml (10 °C); 135 g/100 ml (20 °C); 155 g/100 ml (30 °C); 178 g/100 ml (50 °C); 242 g/100 ml (60 °C); 268 g/100 ml (100 °C)
Solubility in acetone	Soluble
Structure
Crystal structure	Monoclinic
Space group	P21/c
Lattice constant	a = 6.39 Å, b = 6.51 Å, c = 13.90 Å α = 90°, β = 100.3°, γ = 90°
Lattice volume (V)	590.1 Å3
Hazards
	GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H332
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	6348 mg/kg (rat, oral)
Related compounds
Other cations	Calcium chlorate; Strontium chlorate; Barium chlorate
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Magnesium chlorate refers to inorganic compounds with the chemical formula Mg(ClO₃)₂(H₂O)_x. The anhydrous (x = 0), dihydrate (x = 2), and hexahydrate (x = 6) are known. These are thermally labile white solids. The hexahydrate has been identified on the Martian surface.^[3]

Production

Samples of magnesium chlorate were first claimed in 1920 as the result of treating magnesium oxide with chlorine. A more modern method involves electrolysis of magnesium chloride.^[4] The magnesium chlorate can be purified by exploiting its solubility in acetone.^[4]

Properties

The hexahydrate Mg(ClO₃)₂·6H₂O decomposes to the tetrahydrate at 35 °C. At 65 °C, it dehydrates to the dihydrate, then at 80 °C forms a basic salt. If further heated to 120 °C it decomposes to water, oxygen, chlorine, and magnesium oxide.^[2]

As confirmed by X-ray crystallography, the di- and hexahydrates feature octahedral Mg²⁺ centers. The other ligands are water, exclusively in the hexahydrate. In the dihydrate, chlorate is also coordinated and functions as a bridging ligand.^[1]

Uses

Magnesium(II) chlorate is used as a powerful desiccant and a defoliant for cotton, potato, and rice. It is also found as a lubricant in eye drops as an inactive ingredient.^[5]

Hazards

Magnesium chlorate is an oxidizer and can in principle form explosive mixtures.

References

^ ^a ^b ^c Kossev, K; Tsvetanova, L.; Dimowa, L.; Nikolova, R.; Shivachev, B. (2013). "Synthesis and Crystal Structure of Magnesium Chlorate Dihydrate and Magnesium Chlorate Hexahydrate". Bulgarian Chemical Communications. 45: 543–548.
^ ^a ^b ^c ^d Joseph William Mellor (1922). Supplement to Mellor's Comprehensive Treatise on Inorganic and Theoretical Chemistry: suppl. 3. K, Rb, Cs, Fr. Longmans, Green and Company.
^ Ojha, Lujendra; Wilhelm, Mary Beth; Murchie, Scott L.; McEwen, Alfred S.; Wray, James J.; Hanley, Jennifer; Massé, Marion; Chojnacki, Matt (2015). "Spectral evidence for hydrated salts in recurring slope lineae on Mars". Nature Geoscience. 8 (11): 829–832. Bibcode:2015NatGe...8..829O. doi:10.1038/ngeo2546.
^ ^a ^b Herbert Maxim (1948). The electrolytic production of magnesium chlorate and perchlorate. the Department of Chemical Engineering: University of Southern California.
^ "MAGNESIUM CHLORATE". National Center for Advancing Translational Sciences. U.S. Department of Health & Human Services. Retrieved 27 August 2021.

[crys-1] Kossev, K; Tsvetanova, L.; Dimowa, L.; Nikolova, R.; Shivachev, B. (2013). "Synthesis and Crystal Structure of Magnesium Chlorate Dihydrate and Magnesium Chlorate Hexahydrate". Bulgarian Chemical Communications. 45: 543–548.

[:)-2] Joseph William Mellor (1922). Supplement to Mellor's Comprehensive Treatise on Inorganic and Theoretical Chemistry: suppl. 3. K, Rb, Cs, Fr. Longmans, Green and Company.

[3] Ojha, Lujendra; Wilhelm, Mary Beth; Murchie, Scott L.; McEwen, Alfred S.; Wray, James J.; Hanley, Jennifer; Massé, Marion; Chojnacki, Matt (2015). "Spectral evidence for hydrated salts in recurring slope lineae on Mars". Nature Geoscience. 8 (11): 829–832. Bibcode:2015NatGe...8..829O. doi:10.1038/ngeo2546.

[pro-4] Herbert Maxim (1948). The electrolytic production of magnesium chlorate and perchlorate. the Department of Chemical Engineering: University of Southern California.

[5] "MAGNESIUM CHLORATE". National Center for Advancing Translational Sciences. U.S. Department of Health & Human Services. Retrieved 27 August 2021.

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