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Preparation and Investigation of BaSO 4 KMnO 4 Crystals
Author(s) -
Waldeck H.,
Baier E.
Publication year - 1969
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19690040108
Subject(s) - adsorption , miscibility , chemistry , homogeneous , lattice constant , limiting , precipitation , aqueous solution , diffraction , solid solution , crystal (programming language) , analytical chemistry (journal) , thermodynamics , organic chemistry , polymer , mechanical engineering , physics , optics , engineering , meteorology , computer science , programming language
BaSO 4 crystals containing KMnO 4 prepared by precipitation were investigated morphologically, chemically and by X‐ray diffraction. The colour of the preparations is homogeneous and stable. The colour intensity and also the amount of dissolved KMnO 4 (maximum approx. 30 Mol%) increases with concentration of KMnO 4 in the reaction solution to a limiting value dependent on the temperature. The lattice constants or the unit cell volume of the BaSO 4 –KMnO 4 crystals increase with the proportion of KMnO 4 . The experimental values agree well with the Vegard rule for preparations up to 18 Mol% KMnO 4 , but with higher proportions significant departures were observed. They may easily be explained by adsorption phenomena. Because the experimental possibilities for preparation of BaSO 4 ‐KMnO 4 crystals are narrowly limited, the miscibility gap ‐ infered from chemical results ‐ cannot be determined. The system BaSO 4 ‐KMnO 4 is regarded as a true mixed crystal system, nevertheless to explain all observations an adsorption of KMnO 4 on BaSO 4 must also be considered.