Magnesium chlorate refers to

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

s with the

chemical formula A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as pare ...

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.

Production

Samples of magnesium chlorate were first claimed in 1920 as the result of treating

magnesium oxide Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions ...

with

chlorine Chlorine is a chemical element; it has Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate between ...

. A more modern method involves electrolysis of magnesium chloride. The magnesium chlorate can be purified by exploiting its solubility in

acetone Acetone (2-propanone or dimethyl ketone) is an organic compound with the chemical formula, formula . It is the simplest and smallest ketone (). It is a colorless, highly Volatile organic compound, volatile, and flammable liquid with a charact ...

. A more simple method of production is the reaction of barium chlorate and

magnesium sulfate Magnesium sulfate or magnesium sulphate is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, soluble in water but not in ethanol. Magnesi ...

: :Ba(ClO₃)₂ + MgSO₄ → BaSO₄↓ + Mg(ClO₃)₂ The precipitated barium sulfate is filtered to yield a solution of magnesium chlorate, which when evaporated, yields crystals of the hexahydrate.

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 Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

, chlorine, and magnesium oxide. As confirmed by

X-ray crystallography X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...

, 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.

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 A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, ...

in eye drops as an inactive ingredient.

Hazards

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

References

{{Chlorates Magnesium compounds Chlorates