Analysis of magnesium oxide and basic magnesium chloride in anhydrous magnesium chloride
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When preparing anhydrous magnesium chloride in the laboratory, through the analysis of various elements, the composition is as follows: MgO = 0.68% and MgCl2 = 96.7%. How can it be determined whether the MgO is present in its pure form, or as basic magnesium chloride, or perhaps in both forms?
The proportions of the components don’t add up to 100% either; there must be other components as well, right?
This post was last edited by qugd on 2010-4-9 at 16:49. The original poster already said that there is basic magnesium chloride after all.
Anhydrous magnesium chloride is generally prepared by heating hexahydrate magnesium chloride in a hydrogen chloride gas stream to cause dehydration. During this dehydration process, some of the magnesium chloride is converted into basic magnesium chloride. If the analysis results are expressed only in terms of magnesium oxide and magnesium chloride, it is entirely possible that the total amount will not reach 100%, as a considerable portion of hydroxide ions is not taken into account. If expressed in terms of magnesium chloride and basic magnesium chloride, the results may be closer to the actual composition. Additionally, magnesium chloride has a very high water absorption capacity and absorbs water rapidly from the air, which can also affect the analysis results.
Is there any analytical method that can be used to separate magnesium oxide from basic magnesium chloride?