Barium paraperiodate

Barium amalgam, 11 by displacement method, 14 by electrolytic method, 12 Barium paraperiodate, 171 Benzalazine, 92... 

Barium hexafluorosilicate, preparation of, for decomposition to silicon tetrafluoride, 4 145 Barium paraperiodate (orthoperiodate), Ba3H4(I06)2, 1 171 Barium dezZro-tartrate, for resolution of tris(ethylenediamine)-cobalt(III) ion, 6 184 Barium thiocyanate, 3 24 Benzalazine, in recovery of hydrazine residues, 1 92 Benzoylacetone, beryllium derivative of, 2 19... 

The gef for the iodate was calculated from the 298.15 K values in Wagman et al.,1 and the enthalpy increments determined calorimetrically by David et al.12 Unfortunately, equilibrium constants for the above reaction cannot be calculated, because no S°29815 is available for barium paraperiodate. The density at 293 K is 5.23 gem 3.13... 

IOaNa3H2 Sodium paraperiodate, 1 169, 170 2 212 (I06)2BasH4 Barium paraperiodate, 1 171... 

Periodic acid and periodates are the most important, commercially available compounds of iodine(VII). Periodates were first prepared in 1833 by oxidation of NalOs with chlorine in alkaline solutions [727]. The industrial preparation of periodates is based on electrolytic oxidation of iodates. Aqueous solutions of periodic acid are best obtained by treating barium paraperiodate with concentrated nitric acid. In solution it exists as a fairly weak orthoperiodic acid, HsIOe, which can be dehydrated to HIO4 by heating to 100 °C in vacuum [643]. Structural investigations indicate an octahedral configuration about iodine in most periodates [643,728]. 

Section 4.8 and its appendix discuss the action of iodine in more detail. It interacts with other elements to form other precipitates in either NaCl or KO service. These precipitates include barium paraperiodate, and so there may be a synergistic effect when both barium and iodine are present in the brine. Table 4.8.8 lists commercial brine specifications for some of the common membranes [202]. The allowable concentrations of barium and iodine may be related to each other or to operating current density. Table 4.8.9 lists the adverse effeets of various brine impurities. There are reports of physically distinct forms of Ba-I precipitates, with some very fine particles that form in regions away from the main current paths through the membrane [203]. These tend to have relatively little effect on membrane performance [204], and Section 4.8.S.3 also discusses the development of membranes with enhanced resistance to the effects of iodine. 

Ba and I, which can combine under alkaline conditions to form barium paraperiodate ... 

Sodium paraperiodate itself is quite insoluble. In addition, iodine interacts with barium to form the insoluble barium paraperiodate. 

Oxidation of N-Acetyl-D-glucosylamine.98 Six grams (0.027 mole) of N-acetyl-D-glucosylamine (XLI) in 100 cc. of water is added to 18.5 g. (0.081 mole) of paraperiodic acid in 100 cc. of water, and the reaction mixture is maintained at 25° for four and one-half hours, which is known from analytical data obtained in small-scale experiments to be sufficient time for completion of the reaction with the consumption of two moles of the oxidant. The solution is exactly neutralized with barium hydroxide, the precipitate removed, and the filtrate evaporated to dryness in vacuum. The solid is extracted with 100 cc. of absolute ethanol, the ethanol extract evaporated to dryness, the residue taken up in ethanol, and the solution is centrifuged and again evaporated to dryness. The product, the dialdehyde XLII, can be converted into the corresponding barium salt (see reference 93). 

Effect on Membrane Barium, which precipitates as hydroxide or with iodine as paraperiodate, Ba3(H2lOe)2, slightly reduces current efficiency (0.5-1.0%) and causes small voltage increases (approximately 50 mV). 

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