Original scientific paper

Precipitation and Hydrolysis of Thorium in Aqueous Solution. V. Studies of the System: Thorium Nitrate-Ammonium Oxalate

H. Bilinski ; Department of Physical. Chemistry, Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
N. Ingri ; The Royal Institute of Technology, Stockholm, Sweden

Abstract

The precipitation of thorium from aqueous solution of thorium
nitrate (1.25 mM) and ammonium oxalate (2 .5-80 mM) was investigated
at pH from 1 to 10. The following precipitates were identified
with the brutto formula: Th(OH)4 and Th(C204) 2 X 6 H 20 (by means
of chemical ana lyses). The soluble thorium oxalato complex is
formed between these two precipitates and contains 4 oxalate bound
to thorium, with the simples t formula :[Th(C20 4)4
4-] (as determined
by coulometric titration). Using log Ko = 34.8 for the dissolution
constant of thorium hydroxide in ammonium oxalate ~ 4 for thorium
oxalate was obtained: 1.58 X 1024•

Keywords

Hrčak ID:

208069

URI

https://hrcak.srce.hr/208069

Publication date:

15.2.1968.

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