Magnesium and its Compounds

Lithium resembles magnesium, and its compounds show covalent character. Sodium compounds are soluble in water, plentiful, and inexpensive. Potassium compounds are generally less hygroscopic than sodium compounds. 

Careful studies of magnesium and its compounds began in the middle 1700s. Scottish physician and chemist Joseph Black (1728-1799) carried out some of the earliest experiments on magnesium compounds. He reported on his research in an article that became famous. Black is sometimes given credit for discovering magnesium because of his work with the element. 

Describe some uses for (a) calcium and its compounds and (b) magnesium and its compounds. 

Inelastic neutron scattering (INS) measurements on hydrides of magnesium and its compounds... 

Physical and Chemical Properties Magnesium belongs to Group II of the third period of the Periodic Table of elements its atomic weight is 24.312, its atomic number is 12, and the valence is + 2. Natural magnesium consists of three isotopes Mg (79%), Mg (10%), and Mg (11%). The properties of magnesium and its compounds are listed in Table 2.2-1. 

Beryllium is found in some 30 mineral species, the most important of which are bertrandite, beryl, chrysoberyl, and phenacite. Aquamarine and emerald are precious forms of beryl. Beryl and bertrandite are the most important commercial sources of the element and its compounds. Most of the metal is now prepared by reducing beryllium fluoride with magnesium metal. Beryllium metal did not become readily available to industry until 1957. 

Seawater. Salt extraction from seawater is done by most countries having coastlines and weather conducive to evaporation. Seawater is evaporated in a series of concentration ponds until it is saturated with sodium chloride. At this point over 90% of the water has been removed, and some impurities, CaSO and CaCO, have been crystallized. This brine, now saturated in NaCl, is transferred to crystallizer ponds where salt precipitates on the floor of the pond as more water evaporates. Brine left over from the salt crystallizers is called bitterns because of its bitter taste. Bitterns is high in MgCl2, MgSO, and KCl. In some isolated cases, eg, India and China, magnesium and potassium compounds have been commercially extracted, but these represent only a small fraction of total world production. 

Silicon and its compounds are used to add strength to alloys of aluminum, magnesium, copper, and other metals. 

Beryllium (Be, at. mass 9.012) forms cations Be ". In its chemical properties, beryllium resembles magnesium and aluminium. Beryllium hydroxide is precipitated at pH 6, and dissolves in alkali hydroxides. Freshly precipitated Be(OH)2 dissolves in NaaCOs solution to form a rather unstable carbonate complex. Beryllium also forms weak complexes with citrate, tartrate, and fluoride anions. Beryllium and its compounds are highly toxic. 

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