Specification :

Magnesium chloride serves as precursor to other magnesium compounds, for example by precipitation:

MgCl2( aq) + Ca( OH) 2( aq) ’ Mg( OH) 2( s) + CaCl2( aq)
It can be electrolysed to give magnesium metal: [ 5]

MgCl2( l) ’ Mg( l) + Cl2( g)
This process is practiced on a substantial scale.

Magnesium chloride is used for a variety of other applications besides the production of magnesium: the manufacture of textiles, paper, fireproofing agents, cements and refrigeration brine, [ 5] and dust and erosion control. Mixed with hydrated magnesium oxide, magnesium chloride forms a hard material called Sorel cement.

Magnesium ion Mg2+ ( usually added as the chloride) is an important component in the polymerase chain reaction, a procedure used to amplify DNA fragments. It is generally used in experimental biology whenever RNA and DNA and their enzymes are to function in vitro, since Mg2+ is a necessary associate ion for nucleotides in biology, such as ATP.

Magnesium chloride is also used in several medical and topical ( skin related) applications. It has been used in pills as supplemental sources of magnesium, where it serves as a soluble compound which is not as laxitive as magnesium sulfate, and more bioavailable than magnesium hydroxide and magnesium oxide, since it does not require stomach acid to produce soluble Mg2+ ion. It can also be used as an effective anaesthetic for cephalopods, some species of crustaceans, [ 6] and several species of bivalve, including oysters.[ 7]