Magnesium Chloride Anhydrous 98% contains more than 98% magnesium chloride. It is a colorless crystalline solid. The crystal structure of MgCl2 is layer-like. It is very hygroscopic and highly soluble in water and alcohol. It can be prepared by heating hydrated magnesium chloride crystals in a current of dry hydrogen chloride or by heating magnesium ammonium chloride. Magnesium chloride anhydrous has 25.5% elemental magnesium by mass. It is the principal precursor to magnesium metal, which is produced on a large scale.
1. Magnesium chloride serves as a precursor to other magnesium compounds, for example by precipitation: MgCl2(aq) + Ca(OH)2(aq) → Mg(OH)2(s) + CaCl2(aq)
2. Magnesium chloride can be electrolyzed to give magnesium metal: MgCl2(l) → Mg(l) + Cl2(g).
3. Magnesium chloride is an important coagulant used in the preparation of tofu from soy milk.
4. Use as an anti-icer
5. Use in dust and erosion control
6. Use in hydrogen storage
Magnesium chloride is used for a variety of other applications besides the above: the manufacture of textiles, paper, fireproofing agents, cement, and refrigeration brine. Mixed with hydrated magnesium oxide, magnesium chloride forms a hard material called Sorel cement. Magnesium chloride is also used as a reaction component in Polymerase Chain Reaction, a procedure used to amplify DNA fragments.