ISSN:
0377-0486
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The composition of the dissolution layer of certain divalent metal nitrates crystals such as Mg(NO3)2, Ca(NO3)2, Zn(NO3)2 and Cd(NO3)2 in their respective undersaturated solutions was studied by Raman microspectrometry using multi-channel acquisition of data. A preliminary examination of homogeneous saturated and 20% undersaturated solutions of every solute considered confirmed the existence of individual Raman bands which could be assigned to different solvated species, namely free aquated ions, solvent-separated ion pairs and contact ion pairs. Some spectral differences were noted between the four cations involved. With Ca2+, Zn2+ and Cd2+ a weak band, assigned to ion aggregates, was also identified. Micro-Raman spectra of dissolution layers recorded at several steps of the crystal dissolution showed a considerable increase in the proportions of aggregates or contact ion pairs, depending on the type of solute examined. Sharp differences between the dissolution layer composition for Group IA, IIA and IIB metal nitrates were observed.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jrs.1250220306
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