Showing papers on "Potassium iodate published in 1975"
TL;DR: Back-titration procedures involving the use of oxidants such as chloramine T, potassium iodate and iodine are described for the accurate assay of sulphurated sodium borohydride.
Abstract: Back-titration procedures involving the use of oxidants such as chloramine T, potassium iodate and iodine are described for the accurate assay of sulphurated sodium borohydride. Quantitative reactions are completed within 1 h at room temperature for the concentrations and proportions described. The methods are simple, reproducible and accurate within the limits described.
2 citations
TL;DR: In this article, the effect of various reagents on the sorption of zirconium and hafnium on silica-gel from solutions of sulphuric, oxalic and hydrochloric acids and from a mixture of HC1 and KSCN was studied.
Abstract: The effect of phosphoric acid, of phenylarsenic acid (H2L) and of iodate on the sorption of zirconium and hafnium on silica-gel from solutions of sulphuric, oxalic and hydrochloric acids and from a mixture of HC1 and KSCN was studied. It has been found that the sorption increases in media in which neutral complexes are formed; the stability constants for complexes B(HP04)2, B(HP04)3~ and B(L)2 were determined (B denotes the appropriate cation). In the presence of potassium iodate, sorption'of complexes KnB(I03)4 + n is assumed. A method for the separation of zirconium and hafnium from niobium and protactinium has been developed. The present paper deals with the study of the sorption of zirconium and hafnium on silica gel in the presence of reagents with which they form sparingly soluble compounds. A similar problem was treated by Krtil and Kolaffk1, who studied the sorption of zirconium on silica gel from a HN0 3 -H 3 P0 4 medium. However, zirconium is relatively easily sorbed in dilute nitric acid media and the interpretation of the experimental results is thus made difficult. Therefore, media containing sufficiently strong complexing agents were employed in this paper, where the element to be sorbed is masked, but reactions of the cations with the precipitant ions are not prevented. The concentrations of the elements were selected so that the solubility products were not exceeded. Here the most suitable masking agents are solutions of sulphuric and oxalic acids; as reagents forming sparingly soluble compounds with zirconium and hafnium, phosphoric acid and phenylarsenic acid (H2L) and potassium iodate were employed. The study of these systems is useful not only from the point of view of the behaviour of trace amounts of elements in the presence of ions capable of forming precipitates with macro-amounts of the particular elements, which constitutes an important problem in the field of "radiocolloid s", but also from the point of view of separation procedures for substances present in low concentrations, which can be worked out on this principle.
2 citations