Anhydrous magnesium acetate has the chemical formula Mg(C₂H₃O₂)₂ and in its hydrated form, magnesium acetate tetrahydrate, it has the chemical formula Mg(CH₃COO)₂ • 4H₂O. In this compound magnesium has an oxidation state of 2⁺. Magnesium acetate is the

magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ta ...

salt of

acetic acid Acetic acid , systematically named ethanoic acid , is an acidic, colourless liquid and organic compound with the chemical formula (also written as , , or ). Vinegar is at least 4% acetic acid by volume, making acetic acid the main component ...

. It is

deliquescent Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

and upon heating, it decomposes to form

magnesium oxide Magnesium oxide ( Mg O), 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 ...

. Magnesium acetate is commonly used as a source of magnesium in biological reactions.

Physical properties

Magnesium acetate appears as white

hygroscopic Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

crystals. It smells like acetic acid and is soluble in water. When it is in an aqueous solution its pH will be on the alkaline side of neutral.

Storage

Due to the fact that it is very hygroscopic, it must be stored away from water. It is also incompatible with strong oxidizers and should not be mixed with them.

Synthesis

Synthesis of magnesium acetate from the reaction of magnesium hydroxide with acetic acid. :2 CH₃COOH + Mg(OH)₂ → (CH₃COO)₂Mg + 2 H₂O Magnesium carbonate suspended in distilled water with 20% acetic acid solution. :2 CH₃COOH + MgCO₃ → Mg(CH₃COO)₂ + CO₂ + H₂O Reacting metallic magnesium with acetic acid dissolved in dry benzene causes magnesium acetate to form along with the release of hydrogen gas. :Mg +2 CH₃COOH → Mg(CH₃COO)₂ + H₂

Uses and applications

In 1881 Charles Clamond invented the

Clamond basket A Clamond basket is a kind of gas mantle, invented in the 1880s by the Paris, Parisian Charles Clamond, and which he later patented in the United States of America, United States. It was the first economically practical gas mantle, since prior mantl ...

, one of the first effective

gas mantle A Coleman white gas lantern mantle glowing at full brightness An incandescent gas mantle, gas mantle or Welsbach mantle is a device for generating incandescent bright white light when heated by a flame. The name refers to its original heat sou ...

s. The reagents used in this invention included magnesium acetate,

magnesium hydroxide Magnesium hydroxide is the inorganic compound with the chemical formula Mg(OH)2. It occurs in nature as the mineral brucite. It is a white solid with low solubility in water (). Magnesium hydroxide is a common component of antacids, such as milk ...

, and water. Magnesium acetate is commonly used as a source of magnesium or for the acetate ion in chemistry experiments. One example of this is when magnesium acetate and magnesium nitrate were both used to perform molecular dynamics simulations and surface tension measurements. In the experiment the authors found that the acetate had a stronger affinity for the surface compared to the nitrate ion and that the Mg²⁺ strongly repelled away from the air/liquid interference. They also found that the Mg²⁺ had a stronger tendency to bind with the acetate ion compared to the nitrate. One of the more prevalent uses of magnesium acetate is in the mixture called calcium magnesium acetate (CMA). It is a mixture of calcium acetate and magnesium acetate. CMA is thought of as an environmentally friendly alternative deicer to NaCl and CaCl₂. CMA also acts as a powerful SO₂, NO_x, and toxic particulate emission control agent in coal combustion processes to reduce acid rain, and as an effective catalyst for the facilitation of coal combustion. Magnesium acetate has been found to cause a conformational change in ''Escherichia coli'' enzyme

Primase DNA primase is an enzyme involved in the replication of DNA and is a type of RNA polymerase. Primase catalyzes the synthesis of a short RNA (or DNA in some living organisms) segment called a primer complementary to a ssDNA (single-stranded ...

. In this experiment Mg(OAc)₂, MnCl₂, CaCl₂, NaOAc, LiCl, MgSO₄ and MgCl₂ were all compared to see what effect they had on the ''Escherichia coli'' enzyme Primase. The experimenters found that Mg(OAc)₂ caused the best conformational change. MgSO₄ and MgCl₂ induced the effect slightly while the rest did not. When magnesium acetate is mixed with hydrogen peroxide it acts as a bactericidal. Magnesium acetate has been shown to be effective at ashing organic compounds in preparation for a fluorine analysis when high or low concentrations of fluorine are present.

Safety

Magnesium acetate is a relatively safe compound to handle and has been given a health hazard rating of zero. However, it should always be handled with gloves and safety goggles. If it gets in the eyes, the skin, ingested, or inhaled it will cause irritation in the respective areas: eyes, skin, gastrointestinal system, and lungs.

References

{{Acetates Magnesium compounds Acetates