Magnesium Chloride (MgCl2) is an organic compound of two elements: Magnesium and Chlorine. The Hexahydrate form of Magnesium Chloride (MgCl2.7H2O) also contains 6 water molecules. The molecular weight of Magnesium Chloride Hexahydrate is 203.3028 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements and water molecules.
Magnesium Chloride (MgCl2) is soluble in water. Magnesium chloride is available in anhydrous as well as hydrated forms. Since anhydrous Magnesium chloride is hygroscopic (quickly absorbs water from the air), it is convenient to use hydrated forms that are easy to weigh out the right amount accurately. For this reason, Magnesium chloride hexahydrate (MgCl2.6H2O, Molecular Weight: 203.30) is often used to prepare a 1 M Magnesium chloride solution. A 1M stock solution can be prepared by dissolving 203.3 g of MgCl2.6H2O (Molecular Weight: 203.30) in water to a final volume of 100 ml. In the following section, we describe a procedure to prepare 100 ml of 1M MgCl2 stock solution.