An iron(II) solution is often used as a reducing agent in titrimetry and standardized with cerium(IV) or potassium dichromate. Such an iron(II) standard solution is needed for not only titrimetric analyses, but also instrumental ones. Iron(II) is unstable even in a highly acidic solution, mainly due to air-oxidation; therefore, its standardization is required before use. In the present study...

We consider a discrete version of the Brusselator Model of the famous Belousov-Zhabotinsky reaction in chemistry. The original model is a reaction-diffusion equation and its discrete version is a coupled map lattice. We study the dynamics of the local map, which is a smooth map of the plane. We discuss the set of trajectories that escape to infinity as well as analyze the set of bounded traject...

A novel flow injection method has been developed for the indirect determination of uranium by the on-line reduction and subsequent fluorimetric detection of cerium(III). A sample solution containing uranium(VI), prepared as a sulfuric acid solution, was injected into a sulfuric acid carrier solution and passed through a column packed with metal bismuth to reduce uranium(VI) to uranium(IV). The ...

One titrimetric and two spectrophotometric methods are described for the determination of ketotifen fumarate (KTF) in bulk drug and in tablets using cerium(IV) as the oxidimetric agent. In titrimetry (method A), the drug was treated with a measured excess of cerium(IV) in H2SO4 medium and after a standing time of 10 min, the surplus oxidant was determined by back titration with iron(II). The sp...

The structure of cerium(IV) bis-(phosphite), Ce(HPO3)2, has been solved by single-crystal X-ray diffraction and has trigonal (P-3m1) symmetry. The cerium(IV) cation exhibits site symmetry -3m. and is octa-hedrally coordinated by O atoms of the phosphite ligands (point group symmetry 3m.). The highly symmetrical compound has a layered structure parallel to the ab plane, and is closely related to...

Isosorbide is a multi-purpose chemical that can be produced from renewable resources. Specifically, it has been investigated as replacement for toxic bisphenol A (BPA) in the production of polycarbonate (PC). In this study, synthesis isosorbide by sorbitol dehydration using cerium-based catalyst derived calcined cerium (IV) sulfate (300°C, 400°C, 450°C, 500°C, and 650°C) was investigated. The r...

The mixed-valent cerium(III/IV) oxide clusters {Ce(10)} and {Ce(22)}, derived from condensation reactions of cerium carboxylate coordination polymers, exhibit molecular growth tendencies similar to those of 'classical' group V and VI polyoxometalates, but with increasing nuclearity approach the structure of the parental oxide, CeO(2).

Y. Li, J. G. He, X. X. Xue, H. Q. Ru, H. Yang School of Material and Metallurgy, Northeastern University, Shenyang, Liaoning, China. X. W. Huang, National Engineering Research Center for Rare Earth Materials, General Research Institute for Nonferrous Metals, and Grirem Advanced Materials Co., Ltd., Beijing,China In this paper the extraction and separation of cerium/fluorine in fluoride-bearing ...

This study describes an extremely sensitive and simple assay to measure small volumes of solutions, <1 nL. The assay takes advantage of the Sandell-Kolthoff reaction in which yellow cerium(IV) is reduced to colorless cerium(III) in the presence of arsenic(III) and catalytic quantities of iodide ion. The reaction is linear with respect to the rate of Ce(IV) reduction and the quantity of I(-) pre...