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The Behaviour of the System: Gelatin-Ferric Chloride-Neutral Electrolyte-Hydrochloric Acid or Sodium Hydroxide in an Aqueous Medium. II. The Behaviour of the Simpler System: Ferric Chloride -Sodium Hydroxide in an Aqueous Medium

R. H. H. Wolf ; Laboratory of Physical Chemistry, Facuity of Science, University of Zag reb, Zagreb, Croatia, Yugoslavia
B. Težak ; Laboratory of Physical Chemistry, Facuity of Science, University of Zag reb, Zagreb, Croatia, Yugoslavia

Sažetak

The system FeCla-NaOH is one of the simpler systems com:.
posing the four component system gelatin -FeC1 3-NaCl- HCl or NaOH.
The precipitation curve of the system FeC13- N aOH was sys tematically
investigated. Two types of the precipitation curve were founa and discussed. First, the type with two separated maxima: the isoelectric maximum in th e region of the equivalency of the components and the
second one at high NaOH concentrations and high pH values, which
appeared at low FeC13 concentrations. Second, the type with joined
maxima, where the stable negative region between the maxima
disappeared. This type appeared at high FeC13 concentrations. At
intermediate FeC1 3 concentrations the transition type of the precipitation curve was found. The summary diagrams represent the regions of the precipitation curve in dependence on the concentration of the components and the corresponding pH values. A schematic diagram represents the precipitation curve including the maximum of the slow hydrolysis. The increasing age of tl;le system caused: a) an increase of
the turbidity of the negative stable region, b) the dissolution of the
solid phase formed previously, c) the slow hydrolysis of the excess
FeC13 after the systems ha d been prepared.

Ključne riječi

Hrčak ID:

208446

URI

https://hrcak.srce.hr/208446

Datum izdavanja:

1.7.1961.

Posjeta: 552 *