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]
| |
| Names | |
|---|---|
| IUPAC name
Magnesium dichlorate hexahydrate | |
| Systematic IUPAC name
Magnesium dichlorate | |
Other names
| |
| Identifiers | |
|
| |
3D model (JSmol) |
|
| ChemSpider |
|
| ECHA InfoCard | 100.030.634 
|
| EC Number |
|
PubChem CID |
|
| UNII | |
| UN number | 2723 |
CompTox Dashboard (EPA) |
|
| |
| |
| Properties | |
| Mg(ClO3)2 | |
| Molar mass | 191.20 g/mol |
| Appearance | White crystalline solid |
| Density | 1.747 g/cm3 (hexahydrate)[1] |
| Melting point | 35 °C (95 °F; 308 K)[2] |
| Boiling point | 120 °C (248 °F; 393 K)[2] (decomposition) |
| 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)[2] | |
| Solubility in acetone | Soluble |
| Structure[1] | |
| Monoclinic | |
| P21/c | |
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: | |
| |
| Warning | |
| 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).
| |
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]
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]
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]
Magnesium chlorate is an oxidizer and can in principle form explosive mixtures.