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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 Mg 2+ ions and O 2− ions held together by ionic bonding .
After canceling, the equation is re-written as + + + Two ions, positive (Mg 2+) and negative (O 2−) exist on product side and they combine immediately to form a compound magnesium oxide (MgO) due to their opposite charges (electrostatic attraction). In any given oxidation-reduction reaction, there are two half reactions—oxidation half ...
Magnesium oxide is the end product of the thermal decomposition of some magnesium compounds and is usually prepared by igniting carbonates or hydroxides. Magnesium hydroxide is a strong electrolyte, which can be obtained by the reaction of a soluble magnesium salt and sodium hydroxide.
[11] [12] [13] Hydromagnesite decomposes endothermically, [5] [6] giving off water and carbon dioxide, leaving a magnesium oxide residue. The initial decomposition begins at about 220 °C making it ideal for use as a filler in polymers and giving it certain advantages over the most commonly used fire retardant, aluminium hydroxide . [ 14 ]
In both, magnesium oxide is the precursor to magnesium metal. The magnesium oxide is produced as a solid solution with calcium oxide by calcining the mineral dolomite, which is a solid solution of calcium and magnesium carbonates: CaCO 3 ·MgCO 3 → MgO·CaO + 2 CO 2. Reduction occurs at high temperatures with silicon.
Vapor-deposited magnesium crystals from the Pidgeon process. The Pidgeon process is a practical method for smelting magnesium.The most common method involves the raw material, dolomite being fed into an externally heated reduction tank and then thermally reduced to metallic magnesium using 75% ferrosilicon as a reducing agent in a vacuum. [1]
The oxide layer can also be broken up using ultrasound, using a stirring rod to scratch the oxidized layer off, [6] or by adding a few drops of iodine or 1,2-Diiodoethane. Another option is to use sublimed magnesium or magnesium anthracene. [7] "Rieke magnesium" is prepared by a reduction of an anhydrous magnesium chloride with an potassium:
Magnesium nitride reacts with water to produce magnesium hydroxide and ammonia gas, as do many metal nitrides.. Mg 3 N 2 (s) + 6 H 2 O(l) → 3 Mg(OH) 2 (aq) + 2 NH 3 (g). In fact, when magnesium is burned in air, some magnesium nitride is formed in addition to the principal product, magnesium oxide.