Perchlorate ion solutions

The kinetics of the oxidation of chromium(II) by vanadium(ni) in acid perchlorate media have been studied spectrophotometrically between 0.2° and 35.0 °C over a range of 0.027-0.500 M HC104 . The oxygen-sensitivity of both reactants meant that the air had to be excluded in all kinetic runs. Also, since V(III) slowly reduces perchlorate ion, fresh solutions of V(III) were required for each experiment. In terms of stoichiometry the reaction conforms accurately to... 

Neilson, G. W., Schioberg, D. Luck, W. A. P. (1985). The structure around the perchlorate ion in concentrated aqueous solutions. Chemical Physics Letters, 122, 475-9. 

Perchlorates are also produced electrochemicaUy. The oxidation of chlorate to perchlorate ions occurs at a higher positive potential (above 2.0 V vs. SHE) than chloride ion oxidation. The current yield of perchlorate is lower when chloride ions are present in the solution hence, in perchlorate production concentrated pure chlorate solutions free of chlorides are used. Materials stable in this potential range are used as the anodes primarily, these include smooth platinum, platinum on titanium, and lead dioxide. 

Uranyl and Transuranium (V) and (VI) Ions in Aqueous Perchloric Acid Solution. Report LADC-1144 (AECD-3363). J- chem. Phys. 21, 542 (1953). 

A little later, Russell et al.19 tried to obtain methanol from carbon dioxide by electrolysis. Reduction of carbon dioxide to formate ion took place in a neutral electrolyte at a mercury electrode. On the other hand, formic acid was reduced to methanol either in a perchloric acid solution at a lead electrode or in a buffered formic acid solution at a tin electrode. The largest faradaic efficiency for methanol formation from formic acid was ca. 12%, with poor reproducibility, after passing 1900 C in the perchloric acid solution at Pb in a very narrow potential region (-0.9 to -1.0 V versus SCE). In the buffered formic acid solution (0.25 M HCOOH + 0.1 M... 

Interesting results have been obtained from polarographic studies in various donor solvents. Measurements have been made of various metal perchlorates in solutions of donor solvents containing tetraalkylammonium perchlorate as supporting electrolyte against an aqueous saturated calomel electrode 113. In order to eliminate differences in liquid-liquid junction potentials bisbiphenylchromium (I) has been used as a reference ion 114 118). 

Solutions containing perchlorate ion must be handled with care. Their drying may cause explosion. 

Underpotential deposition of Zn on R was seen as adsorption of Zvi ions in 1970, since is as high as 1V, a value that well exceeds the one expected from previous results on various metal combinations of underpotential deposition systems. Recently, Zn underpotential deposition on R was reported in acidic solutions, and then in alkaline solutions. Zn underpotential deposition on Pd was also found in acidic and alkaline solutions. Then cyclic voltammograms of underpotential deposition on three low-index, single-crystal Rs were observed in sulfuric and perchloric acid solutions, as shown in Figs. 27 and 28. " In comparing Figs. 27 and 28, Zn underpotential deposition on R seans to take place only on Pt(llO), but not on Pt(lll) and Pt(lOO). Therefore it can be said that a cyclic voltammogram on polycrystalline R was observed on a R(110)-like surface. 

In situ FTIR for Cu underpotential deposition on Pt( 111) and Rh (111) was observed in sulfuric and perchloric acid solutions." Both adsorbed sulfate and perchlorate species were found on underpotential deposition Cu. The underpotential deposition of T1 on Pt( 111) was observed by FTIR in view of the coadsorption of pachlorate and bisulfate.The IR bands of the adsorbed anions were found to be due to the presence of underpotential deposition metals on Pt(lll), and the possibility of the presence of an ion pair of the underpotential deposition metal and an anion is discussed. 

Under the conditions of the experiments revealing the effect of oxygen (with solutions of chloride, sulfate or perchlorate ions at pH 4 or lower), it was not possible to observe the potential-independent dissolu-... 

Write a balanced net ionic equation to show the reaction of perchlorate ions, C104 , and nitrogen dioxide in acidic solution to produce chloride ions and nitrate ions. 

Since perchlorate ions, and more generally the majority of anions used in common electrolyte systems, are known to move rapidly in liquid solutions, it is reasonable to assume that the rate determining step in controlling the kinetics of the overall process is the ion diffusion throughout the polymer fibrils. This conclusion has been experimentally confirmed. For example, the diffusion coefficient of electrolyte counterions in bulk polyacetylene has been determined (Will, 1985) to be seven orders of magnitude lower than in liquid electrolytes, namely about 10 cm s vs 10 cm s ... 

Pertechnetate in neutral and alkaline media can be extracted into solutions of tetra-alkylammonium iodides in benzene or chloroform. With tetra-n-heptylammo-nium iodide (7.5 x 10 M) in benzene distribution coefficients up to 18 can be obtained . A solution of fV-benzoyl-iV-phenylhydroxylamine (10 M) in chloroform can be used to extract pertechnetate from perchloric acid solution with a distribution coefficient of more than 200, if the concentration of HCIO is higher than 6 M The distribution of TcO between solutions of trilauryl-ammonium nitrate in o-xylene and aqueous solutions of nitrate has been measured. In 1 M (H, Li) NOj and 0.015 M trilaurylammonium nitrate the overall equilibrium constant has been found to be log K = 2.20 at 25 °C. The experiments support an ion exchange reaction . Pertechnetate can also be extracted with rhodamine-B hydrochloride into organic solvents. The extraction coefficient of Tc (VII) between nitrobenzene containing 0.005 %of rhodamine-B hydrochloride and aqueous alcoholic " Tc solution containing 0.0025 % of the hydrochloride, amounts to more than 5x10 at pH 4.7 . 

Upon addition of perchlorate ions to the acetonitrile solutions, the salt [(MeCN)2ln Mn(C0)j 2]C104 can be isolated. This will react with pyridine or phenanthroline to yield [L2ln Mn(C0)5 2]C104 (L = py or phen). The compounds R4N[X4 In Mn(CO)5)J (n = 1—3 R = Me, X = Cl R == Et, X = Br) have also been prepared. Thus this work shows that as well as influencing the amount of dissociation of metal-metal bonded complexes, the nature of the solvent also determines the mode of ionization. The complex [TljMnlCOljlj] can be conveniently prepared from thallium(i) salts and [Na(Mn(CO)g ]. ... 

The effect of fluoride ions on the electrochemical behaviour of a metal zirconium electrode was studied by Pihlar and Cencic in order to develop a sensor for the determination of zirconium ion. Because elemental zirconium is always covered by an oxide layer, the anodic characteristics of a Zr/Zr02 electrode are closely related to the composition of the electrolyte in contact with it. These authors found the fluoride concentration and anodic current density to be proportional in hydrochloric and perchloric acid solutions only. In other electrolytes, the fluoride ion-induced dissolution of elemental zirconium led to an increase in the ZrOj film thickness and hindered mass transport of fluoride through the oxide layer as a result. The... 

Magnesium perchlorate is a strong oxidizing agent. In aqueous solutions and in acid medium the most conspicuous reactions are those involving oxidation—characteristic of the oxidizing action of perchlorate ion, C104. ... 

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