Zum thermischen Verhalten der Hydrogensulfate des Magnesiums,Calciums, Strontiums und Bariums |
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Authors: | E. Kemnitz D. Hass M. Feist H. Worzala D. Menz Ch. Baeker |
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Abstract: | On the Thermal Behaviour of the Hydrogen Sulfates of Magnesium, Calcium, Strontium and Barium The thermal behaviour of the solvent-free crystals of alkaline earth hydrogen sulfates has been investigated. The DTA and TG curves of MII(HSO4)2 indicate a decomposition following the equation Thermal treatment of Mg(HSO4)2 in static gas atmosphere yields α-MgSO4 which is transformed to α-MgSO4 at higher temperature. Contrary to that in dynamic gas atmosphere direct decomposition to α-MgSO4 can be observed. T = 356°C, T = 204°C, T = 175°C, T = 156°C. The strong difference between the peak temperatures of Mg(HSO4)2 and the other alkaline earth hydrogen sulfates may be explained not only through the higher covalency of the bondings in the Mg compound but, especially, through differences of their structures. Whereas the hydrogen sulfates of Ca, Sr, and Ba contain chains of edge-linked MIIO8 polyhedra, in Mg(HSO4)2 exist isolated MgO6 octahedra. |
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