Magnesium chloride
General
Systematic name	Magnesium chloride
Molecular formula	MgCl2 (anhydrous) MgCl2.6H2O (hexahydrate)
Molar mass	95.211 g/mol (anhydrous) 203.31 g/mol (hexahydrate)
Appearance	white or colourless crystalline solid
CAS number	[7786-30-3] (anhydrous) [7791-18-6] (hexahydrate)
Properties
Density and phase	2.32 g/cm3 (anhydrous solid) 1.56 g/cm3 (hexahydrate solid)
Solubility in water	54.2 g/100 cm3 (20 °C)
Solubility in ethanol	7.4 g/100 cm3 (30 °C)
Melting point	714 °C (987 K)
Boiling point	1412 °C (1685 K)
Structure
Coordination geometry	(octahedral, 6-coordinate?)
Crystal structure	CdCl2
Dipole moment	? D
Hydrates	Hexahydrate
Hazards
MSDS	Magnesium chloride MSDS
Main hazards	irritant
NFPA 704
Flash point	?°C
R/S statement	R: ? S: ?
RTECS number	?
Supplementary data page
Structure and properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	magnesium fluoride magnesium bromide magnesium iodide
Other cations	beryllium chloride calcium chloride
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Magnesium chloride is composed of magnesium and chlorine and is a typical ionic halide, being highly polar and soluble in water. It is a weak Lewis acid, so not surprisingly the hexahydrate can undergo partial hydrolysis when heated. Magnesium chloride can be extracted from brine or sea water, and is a commonly used source of magnesium metal, which can be extracted from MgCl₂ using electrolysis. In 1990, US production was around one million tonnes, with a bulk price around $180 per tonne. Magnesium chloride hexahydrate This image has been released into the public domain by its creator and original copyright holder. ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Density (symbol: ρ - Greek: rho) is a measure of mass per volume. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that Solid solubility be merged into this article or section. ... This article describes water from a scientific and technical perspective. ... It has been suggested that Solid solubility be merged into this article or section. ... Ethanol, also known as ethyl alcohol or grain alcohol, is a flammable, colorless, mildly toxic chemical compound with a distinctive perfume-like odor, and is the alcohol found in alcoholic beverages. ... The melting point of a solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... Rose des Sables (Sand Rose), formed of gypsum crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... Cadmium chloride is a white crystalline compound of cadmium and chlorine, with the formula CdCl2. ... The Earths magnetic field, which is approximately a dipole. ... The debye (symbol: D) is a non-SI and non-CGS unit of electrical dipole moment. ... Hydrates are compounds formed by the union of water with some other substance, generally forming a neutral body, as certain crystallized salts. ... A material safety data sheet or MSDS is a form containing data regarding the properties of a particular substance. ... The examples and perspective in this article or section may not represent a worldwide view. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... Risk and Safety Statements, also known as R/S statements, R/S numbers, R/S phrases, and R/S sentences, is a system of hazard codes and phrases for labeling dangerous chemicals and compounds. ... R-phrases are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous substances and preparations. ... S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... The dielectric constant εr (represented as or K in some cases) is defined as the ratio: where εs is the static permittivity of the material in question, and ε0 is the vacuum permittivity. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... IR spectrum of a thin film of liquid ethanol. ... Nuclear Magnetic Resonance Spectroscopy most commonly known as NMR Spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei. ... Basic schematic of a mass spectrometer Mass spectrometry (also know as mass spectroscopy (incorrect)[1] or in common speech mass-spec) is an analytical technique used to measure the mass-to-charge ratio of ions. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss (or addition) of an electron. ... Magnesium fluoride (MgF2) is a white crystalline salt composed of one magnesium ion and two fluoride ions. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss (or addition) of an electron. ... Calcium chloride is a chemical compound of calcium and chlorine. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Atomic mass 35. ... In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ... Hydrolysis is a chemical reaction or process in which a molecule is split into two parts by reacting with a molecule of water, which has the chemical formula H2O. One of the parts gets an OH- from the water molecule and the other part gets an H+ from the water. ... Brine is water saturated or nearly saturated with salt. ... Sea water is water from a sea or ocean. ... It has been suggested that Electrolytic process be merged into this article or section. ... A tonne (symbol t), sometimes referred to as a metric tonne, is a measurement of weight. ...

Chemical properties

Magnesium chloride can serve as a source of magnesium compounds, for example by precipitation:

MgCl₂(aq) + Ca(OH)₂(aq) → Mg(OH)₂(s) + CaCl₂(aq) Drinking water This article focuses on water as we experience it every day. ... Calcium hydroxide is a chemical compound with the chemical formula Ca(OH)2. ... Drinking water This article focuses on water as we experience it every day. ... Magnesium hydroxide, Mg(OH)2, otherwise known as milk of magnesia, is commonly used as an antacid or a laxative. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... Calcium chloride is a chemical compound of calcium and chlorine. ... Drinking water This article focuses on water as we experience it every day. ...

It can be electrolysed to give magnesium metal: It has been suggested that Electrolytic process be merged into this article or section. ... General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ...

MgCl₂(l) → Mg(l) + Cl₂(g) A liquid will usually assume the shape of its container. ... A liquid will usually assume the shape of its container. ... A gas is one of the five main phases of matter (after solid and liquid, and followed by plasma and Bose-Einstein Condensate) and, that subsequently appear as a solid material is subjected to increasingly higher temperatures. ...

Both of these reactions are used in the Dow process for production of metallic magnesium.^[3] Unlike aluminium chloride, hydrated MgCl₂ can be dehydrated without hydrolysis (under certain conditions). This allows anhydrous MgCl₂ to be used as a cheap source of the metal via electrolysis. General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... Aluminium chloride (AlCl3) is a compound of aluminium and chlorine. ...

Magnesium chloride can also act as a weak Lewis acid, and salts containing the MgCl₄^2- are known, though rare.^[2] In chemistry, a Lewis acid can accept a pair of electrons and form a coordinate covalent bond, after the American chemist Gilbert Lewis. ...

Preparation

In the Dow process, magnesium chloride is regenerated from magnesium hydroxide using hydrochloric acid: Magnesium hydroxide, Mg(OH)2, otherwise known as milk of magnesia, is commonly used as an antacid or a laxative. ... The chemical compound hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ...

Mg(OH)₂(s) + 2 HCl → MgCl₂(aq) + 2 H₂O(l) Magnesium hydroxide, Mg(OH)2, otherwise known as milk of magnesia, is commonly used as an antacid or a laxative. ... In jewelry, a solid gold piece is the alternative to gold-filled or gold-plated jewelry. ... The chemical compound hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl) gas. ... Impact of a drop of water. ... A liquid will usually assume the shape of its container. ...

It may also be prepared from magnesium carbonate by a similar reaction. Magnesium carbonate, MgCO3, is a white solid that occurs in nature as a mineral. ...

Uses

Magnesium chloride is used for a variety of applications, besides the manufacture of magnesium via the Dow process discussed above. It is used in the manufacture of textiles, paper, fireproofing agents, cements and refrigeration brine.^[3] General Name, Symbol, Number magnesium, Mg, 12 Chemical series alkaline earth metals Group, Period, Block 2, 3, s Appearance silvery white Atomic mass 24. ... This article is about the type of fabric. ... Piece of A4 paper Paper is a thin, flat material produced by the amalgamation of plant fibres, which are subsequently held together without extra binder, largely by hydrogen bonds and to a small degree by fiber entanglement. ... Fireproofing, a passive fire protection measure, subject to bounding, refers to the act of making materials or structures more resistant to fire, or to those materials themselves. ... In the most general sense of the word, cement is a binder, a substance which sets and hardens independently, and can bind other materials together. ... It has been suggested that Refrigerator be merged into this article or section. ...

Culinary use

Magnesium chloride is an important coagulant used in the preparation of tofu from soy milk. In Japan it is sold as nigari (the term is derived from the Japanese word for "bitter"), a white powder produced from seawater after the sodium chloride has been removed, and the water evaporated. Nigari consists mostly of magnesium chloride, with some magnesium sulfate and other trace elements. Tofu, also called doufu (often in Chinese recipes) or bean curd (literal translation), is a food of Chinese origin, made by coagulating soy milk, and then pressing the resulting curds into blocks. ... A can of Yeos soy milk, poured into a glass Soy milk (also called soymilk, soya milk, soybean milk, soy bean milk, soy drink, or soy beverage) is a milk-like beverage made from soybeans. ... Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the formula NaCl. ... Magnesium sulfate or Magnesium sulfate heptahydrate or Epsom salt is a chemical compound containing magnesium, with the formula MgSO4·7H2O. Magnesium sulfate without water of crystalization MgSO4 is available as a far less common chemical and drying agent, but typically magnesium sulfate refers to the hydrate, and Epsom salt always...

Use as an anti-icer

A number of state highway departments throughout the United States have decreased the use of rock salt and sand on roadways and have increased the use of liquid magnesium chloride as a de-icer or anti-icer. The liquid magnesium chloride is sprayed on dry pavement (tarmac) prior to precipitation or wet pavement prior to freezing temperatures in the winter months to prevent snow and ice from adhering and bonding to the roadway. The application of anti-icers is utilized in an effort to improve highway safety. The use of this product seems to show an improvement in driving conditions during and after freezing precipitation yet it seems to be negatively affecting electric utilities. Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with formula NaCl. ...

Two main issues have been raised regarding the anti-icer magnesium chloride as it relates to electric utilities: contamination of insulators causing tracking and arcing across them, and corrosion of steel and aluminium poles and pole hardware. General Name, Symbol, Number aluminium, Al, 13 Chemical series poor metals Group, Period, Block 13, 3, p Appearance silvery Atomic mass 26. ...

Use in Hydrogen Storage

Magnesium chloride has shown promise as a storage material for hydrogen. Ammonia, which is rich in hydrogen atoms, is used as an intermediate storage material. Ammonia can be effectively absorbed to solid Magnesium chloride, forming Mg(NH3)6Cl2. Ammonia is released by mild heat, and is then passed through a catalyst to give hydrogen gas. General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ...

Precautions

Irritant. Wear gloves and goggles. For more details see a MSDS-sheet.

References

1. Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.
2. N. N. Greenwood, A. Earnshaw, Chemistry of the Elements, Pergamon Press, 1984.
3. Hill, Petrucci, McCreary, Perry, "General Chemistry", 4th ed., Pearson/Prentice Hall, Upper Saddle River, New Jersey, USA.

External links

• Magnesium Chloride as a De-Icing Agent

• Link page to external chemical sources.

Suppliers/Manufacturers

• EMD Chemicals