Oxidizing agents ferrate

Iron(VI) ferrates are easily prepared, stable solids. They are strong oxidizing agents (E° = -h 0.72 V in alkaline solution) and show a high degree of selectivity. In aqueous basic solution the ion is FeO " all O s are equivalent towards H2O exchange. At pH 9.6-14,... 

Iron can assume the oxidation states - -2, -f 3, and +6, the last being rare, and represented by only a few compounds, such as potassium ferrate, KoFeO. The oxidation states -f 2 and +3 correspond to the ferrous ion, Fe+ +, and ferric ion, Fe + +, respectively. The ferrous ion is easily oxidized to ferric ion, by air or other oxidizing agents. Both ferrous and ferric ion form complexes, such as the ferrocyanide... 

Schemes have been devised to substitute less toxic metals for more toxic ones. Potassium ferrate on K10 mont-morillonite clay has been used to replace potassium chromate and potassium permanganate in the oxidation of alcohols to aldehydes and ketones in 54-100% yields.153 The potassium ferrate is made by the action of sodium hypochlorite on iron(III) nitrate or by treatment of iron(III) sulfate with potassium peroxymonosulfate.154 After the oxidation, any excess oxidizing agent, and its reduced form, are easy to recover by filtration or centrifugation. In another case, manganese-containing reagents have been substituted for more toxic ones containing chromium and selenium (4.21).155 Selenium dioxide was used formerly in the first step and pyridinium chlorochromate in the second.

The ruby-red salt K3[Fe(CN)g] (potassium hexacyano-ferrate(III) or ferricyanide) is commercially available. It is an oxidizing agent although [Fe(CN)g] is less powerful an oxidant than [Fe(H20)g] (see Section 7.3). Addition of [Fe(CN)g] to aqueous Fe + gives the deep blue complex Turnbull s blue and this reaction is used as a qualitative test for Fe +. Conversely, if [Fe(CN)g] is added to aqueous Fe, the deep blue complex Prussian blue is produced. Both Prussian blue and Turnbull s blue are hydrated salts of... 

The ruby-red salt K3[Fe(CN)6] (potassium hexacyano-ferrate(III) or ferricyanide) is commercially available. It is an oxidizing agent although [Fe(CN)6 is less powerful an oxidant than [Fe(OH2)6] (see Section 8.3). Addition of... 

Iron can assume the oxidation states+2, +3, and +6, the last being rare, and represented by only a few compounds, such as potassium ferrate, KaFeOj. The oxidation states +2 and +3 correspond to the ferrous ion, Fe ", and ferric ion, Fe, respectively. The ferrous ion has six electrons in the incomplete 2>d subshell, and the ferric ion has five electrons in this subshell. The magnetic properties of the compounds of iron and other transition elements are due to the presence of a smaller number of electrons in the 3td subshell than required to fill this subshell. For example, ferric ion can have all five of its 2>d electrons with spins oriented in the same direction, because there are five 2>d orbitals in the 3d subshell, and the Pauli principle permits parallel orientation of the spins of electrons so long as there is only one electron per orbital. The ferrous ion. is easily oxidized to ferric ion by air or other oxidizing agents. Both bipositive and terpositive iron form complexes, such as the ferrocyanide ion, Fe(CN)e and the ferricyanide ion, Fe(CN)e, but they do not form complexes with ammonia. 

The ferrate ion, Fe04 , is such a powerful oxidizing agent that in acidic solution, aqueous ammonia is reduced to elemental nitrogen along with the formation of the iron(III) ion. 

Iron(Vl) in the form of ferrate ion, Fe04, is a strong oxidizing agent with excellent disinfectant properties. It has the additional advantage of removing heavy metals, viruses, and phosphate. It may well find limited applieation for disinfection in the future. 

The anodic photocurrent of n-Si in aqueous solutions in the absmce of fluoride decays very rapidly due to the formation of an oxide film. It decays less rapidly in the presence of a reducing agent which can compete efficiently for the holes from the valence band and slow down the rate of oxidation. Ferrate ions and iodine ions have been found to compete favorably with the oxidation of the silicon surface. On the other hand, in solutions containing a small amount of fluoride ions insufficient to completely remove the oxide film, the photocurrent exhibits a fast decay. According to Matsumura and Morrison, the rapid decay of the photocurrent in solutions with a small amount of fluoride is due to the catalytic effect of fluoride ions at the Si/SiO interface. 

COBALT DINITRATE (10141-05-6 10026-22-9, hexahydrate) A strong oxidizer. Violent reaction with reducing agents, powdered aluminum, ammonium hexacyano-ferrate(ll), boron phosphide, carbon, combustible materials, cyanide, esters, fuels, organic materials, sodium hypophosphite, phosphorus, sodium cyanide, stannous chloride, thiocyanates. Incompatible with acetylene. 

NITRIC ACID, MAGNESIUM SALT (10377-60-3) A powerful oxidizer. Reacts violently with dimethylformamide, reducing agents, combustible materials, fuels, organic substances, metal powders, potassium hexanitrocobalite(III) (C.I. pigment yellow), sodium acetylide, and easily oxidizable matter. Incompatible with aluminum, ammonium hexacyano-ferrate(II), tert-butylhydroperoxide, citric acid, ethanol, ferrocyanides, hydrazinium perchlorate, isopropyl chlorocarbonate, metal phosphinates, nitrosyl perchlorate, organic azides, phosphorus, sodium thiosulfate, sulfamic acid, thiocyanates, tin(II) fluoride, and many other substances,... 

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