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The precipitation of alkaline‐earth metal molybdate powders from aqueous solution. Crystal numbers, final morphology and sizes
Author(s) -
Packter A.
Publication year - 1977
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.19770120709
Subject(s) - molybdate , precipitation , strontium , barium , alkaline earth metal , aqueous solution , metal , solubility , crystal growth , crystal (programming language) , inorganic chemistry , tetragonal crystal system , salt (chemistry) , chemistry , materials science , mineralogy , crystal structure , crystallography , metallurgy , programming language , physics , organic chemistry , meteorology , computer science
The precipitation of barium, strontium and calcium molybdates was studied from neutral equivalent solutions of concentrations from 0.0004 to 0.4 M at 25 °C. Crystal growth started after induction periods; the precipitiations were heterogeneously nucleated at low supersaturations and homogeneously nucleated at medium to high supersaturations. Barium molybdate was precipitated as tetragonal bipyramids, strontium molybdate generally as prisms and calcium molybdate as platelets. Crystal numbers at medium to high supersaturations increased with increasing inital metal molybdate concentrations according to the relation,\documentclass{article}\pagestyle{empty}\begin{document}$$ N = N_1 C_0^2 . \\ $$\end{document}The final crystal lengths in this range than decreased from maximum values (at the critical concentrations) with increasing initial metal molybdate concentrations according to the relation.\documentclass{article}\pagestyle{empty}\begin{document}$$ l_{fin} = l_1 /C_0^2 \\$$\end{document}Generally, for precipitation from solutions at any concentration, larger crystals were obtained in the precipitates of the salt of higher solubility.