Magnesium chloride is a compound that consists of magnesium and chloride ions. It can be prepared by several methods, but one of the most common and practical ways to obtain pure magnesium chloride is by the reaction of magnesium oxide or magnesium hydroxide with hydrochloric acid. The essential practical details for the preparation of pure magnesium chloride are as follows:
Start with high-quality chemicals: Ensure that the magnesium oxide or magnesium hydroxide and hydrochloric acid used in the reaction are of high purity and quality.
Prepare the reaction mixture: Add a calculated amount of magnesium oxide or magnesium hydroxide to the hydrochloric acid in a reaction vessel. The reaction is exothermic, so it is important to add the magnesium oxide or magnesium hydroxide slowly to avoid overheating.
Stir the mixture: The reaction mixture should be stirred continuously using a magnetic stirrer to ensure uniform mixing and prevent the formation of lumps.
Heat the mixture: The reaction mixture should be heated using a heating mantle or hot plate to speed up the reaction. The temperature should be maintained below 100°C to prevent the formation of magnesium oxychloride.
Monitor the progress of the reaction: The reaction is complete when all the magnesium oxide or magnesium hydroxide has dissolved, and the solution is clear.
Filter the solution: The solution is then filtered to remove any insoluble impurities or byproducts.
Concentrate and crystallize the solution: The solution is concentrated by evaporation to increase the concentration of magnesium chloride. The solution is then allowed to cool slowly to room temperature to allow the formation of pure magnesium chloride crystals.
Dry and store the magnesium chloride: The crystals are then filtered, washed with cold water, and dried in an oven. The pure magnesium chloride can then be stored in airtight containers for future use.
Overall, the preparation of pure magnesium chloride involves careful attention to detail, including the use of high-quality chemicals, controlled heating and stirring, and monitoring the progress of the reaction to ensure the production of high-quality crystals.