Lead, oxidation with

Interaction of lead oxide with bromide salts in phenol at the ratio Br PbO less than 2 yields the precipitation of white sediments with the general formula PbnOm(OPh)(2.z)(n-m)Brz(n-m), where n = 4 - 10, m = 1 - 4, z = 0 - 1 and formation of (n-m) moles of water. Reaction takes place in the presence of a variety of bromide salts including quaternary and alkali metal bromides. In the latter case, the presence of acoordinating solvent, e.g. MeCN, is necessary. The composition of product lead bromophenoxides depends on the Br PbO ratio, bromide salt and solvent. These complexes usually have Pb 0 ratio of 4 1 or 3 1, and variable levels of bromide (including some bromide-free complexes) (Table 3). 

Strangely enough, a combination similar to the ammonia catalyst, iron oxide plus alumina, yielded particularly good results (32). Together with Ch. Beck, the author found that other combinations such as iron oxide with chromium oxide, zinc oxide with chromium oxide, lead oxide with uranium oxide, copper oxide with zirconium oxide, manganese oxide with chromium oxide, and similar multicomponent systems were quite effective catalysts for the same reaction (33). 

Fig. 3.2 XRD spectra showing the process of PbSe formation from the reaction of precipitated hydrated lead oxide with Na2SeS03 solution, (a) Starting material (b-e) after 1.5, 3, 4.5, and 6 mn reaction, respectively. (Adapted from Ref. 46.)... 

The earliest preparations of carbodiimides involved the reaction of mercuric or lead oxide with thioureas [6-10]. 

Nitrates and Nitrites. — Mix 1 gm. of lead oxide with 5 cc. of water, and dissolve with the aid of 5 cc. of dilute acetic acid. The blue color produced by adding 1 drop of indigo... 

Lead Chlorate(Basic), Pb(C103)2.Pb(OH)2 mw 615.35, wh solid can be prepd by treating 2 mols of lead oxide with 2 mols of hot coned chloric acid. There are also Dibasic and Tribasic salts... 

Lead carbonate is prepared by treating an aqueous slurry of lead oxide with acetic acid in the presence of air and carbon dioxide ... 

Soils that have been contaminated by mine wastes, tailings, smelter slags, or smelter particulates can contain a complex mixture of minerals present in the soils prior to contamination minerals contributed by the contaminants minerals formed by soil weathering, biological reactions, and chemical reactions with infiltrating waters and soil moisture windblown dust, and other anthropogenic materials (Ruby et al, 1999). For example, reactions of lead oxide with soil moisture in alkaline soils can precipitate lead carbonate, whereas reactions in acidic soils can precipitate lead sulfate. 

Azoxybenzene has been prepared by reduction of nitrobenzene with alcoholic potassium hydroxide, with sodium amalgam, with hydrogen in the presence of lead oxide, with methyl alcohol and sodium hydroxide, with sodium methylate and methyl alcohol, and by electrolytic reduction by oxidation of azobenzene with chromic anhydride by treatment of /9-phenylhydroxylamine with alkaline potassium permanganate, with nitrobenzene, with mineral acids, and with mercury acetamide, and by oxidation of aniluie with hydrogen peroxide, and with acid permanganate solution in the presence of formaldehyde. The procedure described above is a slight modification of one described in the literature. ... 

The Hungarian chemist Mezaros1 states that pyrophoric lead can be prepared by reaction of lead oxide with furfural vapors at 290°. It can be purified by washing with benzene and aqueous alcohol. It is described as a new reagent for Wurtz-like reactions, for example ... 

T. Shimizu, Studies on Mixtures of Lead Oxides with Metals (Magnalium, Aluminum, or M gnesium) , Pyrotechnica XIII, 1990. 

During the past decade, nanotechnologies have found application in the manufacture of a number of products. Attempts have been made to obtain lead oxide with nano-sized particles under laboratory conditions. Synthesis of a-PbO with nano-crystal structure is achieved through two chemical reactions [26,27]. The first reaction is between solutions of Pb(N03)2 and Na2C03 ... 

In an interesting find, a lead stearate source based method with oleylamine-selenium was reported over the usual use of lead oxide with trioclylphosphine-selenium for the preparation of monodispered PbSe... 

Lead Silicate. A material obtained by fritting lead oxide with silica in various ratios. The usual ratio approximates to Pb0.2Si02 and a frit of this composition is known as lead bisilicate a specification (Trans. Brit. Ceram. Soc., 50,255,1951) is 63-66% PbO, 2-3.5% AI2O3, and PbO + Si02 + AI2O3 to exceed 98%. A lead solubility test (q.v.) is also specified. The bisilicate is used in pottery glazes. 

Lead reduction tends to occur in the top zone of the furnace by reaction of lead oxides with zinc vapour and with CO. The reactions are mildly exothermic. 

T. Shimizu, Studies on mixtures of lead oxides with metals (magnalium, aluminum, or magnesium), in Pyrotechnica XIII, Austin, TX Pyrotechnica Publications, 1990. 

The lead oxidation process is exothermic and the generated heat is essential for sustaining a continuous reaction as more lead is introduced. The process temperature is critical for determining the degree of oxidation and crystal morphology of the lead oxide. The Barton pot process typically produces a product containing lead oxide with 15% to 30% free lead, which exists as the core of the lead oxide spherically shaped particles. Figure 7.8 shows a Barton pot. 

Urazov et al. (1956) Urazov, G.G. Speranskaya, E.I. Gulyanitskaya, Z.E Physico-chemical study of the reaction of lead oxide with the oxides of antimony and tin Russian Journal of Inorganic Chemistry 1 6 (1956) 307-311 Ure (1839) Ure, A. A Dictionary of Arts, Manufacturers, and Mines London (1839)... 

Also, monobasic lead sulfate has been used as a pre-sulfated paste material (14). However, positive plates prepared from such pre-sulfated paste mixes are difficult to form and must usually be cured for at least 24 hours before being formed (15). It is also known that reacting lead oxide with ozone forms improved lead oxides useful as active materials in batteries (16). 

Miscellaneous Curatives include piedispersed curative packages, PAPI (a polyisocyanate) and NBC (nickel dibutyldithiocarbamate). Poly-dispersion HC-11 is a curative package based on an activated lead oxide with undisclosed curatives in an elastomeric dispersing agent. This is fine for many applications as it provides simplicity, process safety, bin stability, and adequate rate and state of cure. PAPI... 

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