Description
Anhydrous Magnesium Acetate has the chemical formula Mg(CH
3COO)
2 and in its hydrous form, Magnesium Acetate Tetrahydrate, it has the chemical formula Mg(CH
3COO)
2.4H
2O. In this compound the magnesium metal has an oxidation state of 2
+.
Magnesium acetate is the magnesium salt of acetic acid.It is deliquescent and upon heating, it decomposes to form magnesium oxide.Magnesium acetate is commonly used as a source of magnesium or as a chemical reagent.
Chemical Properties
Anhydrous magnesium acetate, a white, crystalline, deliquescent solid, occurs in two forms: α-Mg(C2H3O2)2, formed by the reaction of MgO and concentrated acetic acid (13–33%) in boiling ethyl acetate, an and β-Mg(C2H3O2)2 which is formed using 5–6% acetic acid.
Chemical Properties
white deliquescent crystals
Physical properties
Magnesium acetate appears as white hygroscopic crystals. It smells like acetic acid and is soluble in water. When it is in an aqueous solution its pH can be considered to be neutral.
Characteristics
In 1881 Charles Clamond invented the Clamond basket, one of the first effective gas mantles. The reagents used in this invention included magnesium acetate, magnesium hydroxide 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, NOx, 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.
Definition
ChEBI: The magnesium salt of acetic acid.
Flammability and Explosibility
Nonflammable
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 is gets in the eyes, the skin, ingested, or inhaled it will cause irritation in the respective areas: eyes, skin, gastrointestinal system, and lungs.
Synthesis
Synthesis of magnesium acetate from the reaction of magnesium hydroxide with acetic acid.
2CH3COOH + Mg(OH)2 → (CH3COO)2Mg + 2H2O
Magnesium carbonate suspended in distilled water with 20 % acetic acid solution.
2CH3COOH + MgCO3 → Mg(CH3COO)2
Reacting metallic magnesium with acetic acid dissolved in dry nitrogen benzene causes Magnesium Acetate to form along with the release a gas, presumably hydrogen.
Mg +2CH3COOH → Mg(CH3COO)2 + H2.
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.
Purification Methods
Crystallise it from anhydrous acetic acid, then dry it under vacuum for 24hours at 100o. [Nencollas J Chem Soc 744 1956, Beilstein 2 IV 113.]
