Ferrous bromate

Ferrous bromate, Fe(Br03)2, is obtained in regular octahedra on dissolving ferrous carbonate in bromic acid and concentrating in vacuo. 

Ferrous Sulfdte Titration. For deterrnination of nitric acid in mixed acid or for nitrates that are free from interferences, ferrous sulfate titration, the nitrometer method, and Devarda s method give excellent results. The deterrnination of nitric acid and nitrates in mixed acid is based on the oxidation of ferrous sulfate [7720-78-7] by nitric acid and may be subject to interference by other materials that reduce nitric acid or oxidize ferrous sulfate. Small amounts of sodium chloride, potassium bromide, or potassium iodide may be tolerated without serious interference, as can nitrous acid up to 50% of the total amount of nitric acid present. Strong oxidizing agents, eg, chlorates, iodates, and bromates, interfere by oxidizing the standardized ferrous sulfate. 

This mechanism can be illustrated by the reaction of ferrous ions with hydrogen peroxide (42), the reduction of organic peroxides by cuprous ions (63), as well as by the reduction of perchlorate ions by Ti(III) (35), V(II) (58), Eu(II) (71), The oxidation of chromous ions by bromate and nitrate ions may also be classified in this category. In the latter cases, an oxygen transfer from the ligand to the metal ion has been demonstrated (8), As analogous cases one may cite the oxidation of Cr(H20)6+2 by azide ions (15) (where it has been demonstrated that the Cr—N bond is partially retained after oxidation), and the oxidation of Cr(H20)6+2 by 0-iodo-benzoic acid (6, 8), where an iodine transfer was shown to take place. 

In the BZ reaction, malonic acid is oxidized in an acidic medium by bromate ions, with or without a catalyst (usually cerous or ferrous ions). It has been known since the 1950s that this reaction can exhibit limit-cycle oscillations, as discussed in Section 8,3. By the 1970s, it became natural to inquire whether the BZ reaction could also become chaotic under appropriate conditions. Chemical chaos was first reported by Schmitz, Graziani, and Hudson (1977), but their results left room for skepticism—some chemists suspected that the observed complex dynamics might be due instead to uncontrolled fluctuations in experimental control parameters. What was needed was some demonstration that the dynamics obeyed the newly emerging laws of chaos. 

Potassium Bromid—Potassii bromidum (Tr. S. Br.)—KBr—119 —is formed, either by decomposing ferrous bromid by KaCOa, or by dissolving Br in solution of KHO. In the latter case the bromate formed is converted into KBr, by calcining the jiroduct. It crystallizes in anhydrous cubes or tables has a sharp, salty taste very soluble in HaO, sparingly so in alcohol. It is decomposed by Cl with liberation of Br. 

Typical examples of applications include the titration of ferrous ion with permanganate the titration of arsenic(III) with bromate the determination of ascorbic acid with iodine and the determination of organic compounds such as azo, nitro, and nitroso compounds and quinones with chromous ion. 

The e.s.r. spectra of oxovanadium ions in redox systems have been reported. The interaction of free-radicals generated using the reactions of cerium(iv) or ferrous ions with hydrogen peroxide with oxovanadium(v), produces a complex which decays in a first-order manner (k = 6-2 s at 22 °C) with the formation of vanadium(iv). The oxidation of phenetidines by bromate is catalysed by vanadium(v) and kinetic parameters involved in the interactions of various substrates with vanadium(v) have been correlated with electron configurations. The redox behaviour of oxo-3,5-disulphocatecholatovanadium(v) has been studied and the acidity dependence in the reaction with phenylethyl alcohol reported. In the... 

A number of procedures were investigated in an effort to find an approach that preferentially removes chlorite without adversely affecting bromate levels. Of these, the procedure that employs Fe(II) in acidic solution was found to be the most effective [33]. Removing residual chlorite from drinking water using ferrous iron under slightly acidic (pH 5-6.5) conditions has been extensively studied [34]. The molar stoichiometry, based on Eq. (296), predicts that 3.3 mg of Fe(II) would be required to completely reduce 1.0 mg C102 [35]. 

Many of the experimental results presented in this chapter were obtained in ferroin-catalyzed BZ systems prepared according to the following standard procedure. Solutions were prepared with reagent-grade chemicals and distilled water. The three initial reactant solutions were sodium bromate in sulfuric acid, sodium bromide in water, and malonic acid in water. A 25 mM solution of ferroin, the tris(l, 10-phenanthroline) ferrous sulfate complex, was prepared by dissolving stoichiometric amounts of phenanthroline and ferrous sulfate in 25 mM sulfuric acid. All solutions were filtered through 0.44-jim Millipore filters and stored in separate containers. Concentrations were calculated from the weights of the dissolved chemicals. 

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