Physical and Chemical Properties of Magnesium Oxide

The physical and chemical properties of magnesium oxide are primarily governed by the source of the precursor, that is, derived from magnesite or precipitated from brine or seawater. Other important factors include time and temperature of calcination and the presence of trace impurities. Electron microscope studies have revealed that the precursor particle morphology has a large impact on the morphology of the final MgO particle. It has been shown that when brucite and magnesite crystals are thermally decomposed at low temperatures, pseudomorphs of a size and shape similar to the parent crystal are formed. 

Table 3.6 Physical and Chemical Properties of Magnesium Oxide Whiskers...

Plasma electrolytic oxidation (PEO) is an efficient method for production of functional ceramic surface layers on non-ferrous metals, such as aluminium, magnesium, zirconium and titanium alloys. During PEO process the electrochemical reaction of anodic oxidation on the metal surface is assisted by micro-discharge events to promote formation of thick, hard and well-adhered oxide ceramic surface layers with specific morphologies and phase compositions, exhibiting superior protective performance and other useful electro-physical and chemical properties. ... 

Comparing the two relative forces of electrostatic attraction that you calculated, you can conclude that ionic bonding is considerably stronger in magnesium oxide. This affects the physical properties and chemical behavior of the two compounds. For example, the melting point of MgO (2,852° C) is much higher than that of LiF (845° C). 

Physical and chemical as well catalytical properties of basic oxides depend on the nature of the compound from which the oxide has been prepared. MgO is mostly prepared from soluble magnesium salts, (the nitrate, chloride and acetate are mostly used) by precipitation from aqueous solution and calcination of Mg(0H)2<... 

Recall that salts are ionic compounds made of cations and anions. Many of the rocks and minerals in Earth s crust are made of cations and anions held together by ionic bonds. The ratio of cations to anions is always such that an ionic compound has no overall charge. For example, in sodium chloride, for every Na" cation, there is a Cl anion to balance the charge. In magnesium oxide, for every Mg " cation, there is an O anion. Ionic compounds also share certain other chemical and physical properties. 

---