Barium oxide properties

Barium is prepared commercially by the thermal reduction of barium oxide with aluminum. Barium metal is highly reactive, a property which accounts for its principal uses as a getter for removing residual gases from vacuum systems and as a deoxidiser for steel and other metals. 

Barium nitrate is prepared by reaction of BaCO and nitric acid, filtration and evaporative crystallization, or by dissolving sodium nitrate in a saturated solution of barium chloride, with subsequent precipitation of barium nitrate. The precipitate is centrifuged, washed, and dried. Barium nitrate is used in pyrotechnic green flares, tracer buUets, primers, and in detonators. These make use of its property of easy decomposition as well as its characteristic green flame. A small amount is used as a source of barium oxide in enamels. 

Barium nitrate is superior to either sodium or potassium nitrate with regard to physical stability, while the heat concentration is also higher because barium oxide has better refractory properties than does either potassium or sodium oxide. 

Barium Arsenide, Ba3As2.—By passing arsine over barium oxide at red heat Soubeiran 4 obtained a mixture of arsenide and arsenite. Lebeau 6 prepared the pure arsenide by reduction of barium arsenate with carbon in an electric furnace. Barium arsenide is very similar in properties to the arsenides of calcium and strontium it is slightly darker in colour, more readily fusible and more reactive chemically. Its density at 15° C. is 4-1. It burns spontaneously in fluorine, chlorine or bromine vapour. In oxygen it burns at about 300° C. and in sulphur vapour at dull red heat. 

It was shown in [18] that practically monophase fine barium hexaaluminate can be obtained by mechanical activation of a mixture of barium oxide with Y-AI2O3, which exhibits acid properties to a larger extent than a-Al203, and by consequent thermal treatments at increased temperature. The product then is grinded in the presence of water. The synthesis was shown to proceed almost completely after activation for 5 min in the AGO-2 planetary mill and thermal treatment at 1300°C for 1 h. Mechanical activation of the mixture of aluminium hydroxide with barium oxide, followed by thermal treatment at 900°C, results in the formation of the final product and a-Al203 as an admixture which remains even at 1300°C. Mechanochemical synthesis helped also to synthesize barinm hexaaluminate in which a part of aluminium cations is replaced with manganese, iron, cobalt cations. Such compounds are nsed as active ceramics in catalysis [17]. 

An extensive series of phases of general formula Ba Ti5,0 +2y are formed from the reaction of Ti02 with barium oxide. The simplest, BaTiOs, is known as barium titanate. These materials are of interest because of their ferroelectric properties, which result from the differences in the relative sizes of the Ba andTi ions. The Ti ions are located between six Ba ions, which occupy octahedral positions. However, the Ti ions are small compared to the Ba and so are free to move within their octahedral Ba holes . 

Preparation, Properties, and Structure of Hydrogen Peroxide. When barium oxide, BaO, is heated to a dull red heat in a stream of air it adds oxygen to form a similar compound, BaO, barium peroxide ... 

Barium nitrate would be the best of the three from the standpoint of physical stability and also of heat concentration because barium oxide has considerably better refractory properties than either potassium or sodium oxide. However, the high equivalent weight of barium limits its usefulness. Barium and strontium nitrates are indispensable for green and red effects and can also be used combined for white light. In combination with potassium perchlorate and aluminum, barium nitrate is part of standard photoflash powder. Ammonium and guanidine nitrate are sometimes used because of their gas-forming properties, and lead and silver nitrate can be found in special applications. 

Barium Petronate 50-S Neutral. See Barium petroleum sulfonate Barium protoxide. See Barium oxide Barium ricinoleate Synonyms Barium 12-hydroxyoleate Empin cal CseHeeBaOe Properties M.w. 732.36 Uses Heat stabilizer for PVC Barium silicide Formula BaSi2... 

Electrical neutrality is assured by an electronic part composed of free or trapped electrons, which lends this group the properties of a semiconductor n. We can cite barium oxide BaO as an example of a substance that belongs to this family. 

We note here that CTV neck and funnel glasses often contain between 20 and 30 wt% PbO. Because of the tendeney for electron browning mentioned in Sec. 6.1.2.2, current panel glasses contain less than 5 percent PbO, and sometimes none. Barium oxide (BaO), strontium oxide (SrO), and zirconium oxide (ZrOj) provide the required magnitude of x-ray absorption. Tables 6.7 and 6.8 show compositions and properties for several commercial TV panel glasses. 

The investigation of the Ba-Fe-0 ternary system is concerned mainly with the study of BaFei20i9 and related compounds, which have magnetic properties of significant practical importance (Table 1). Barium oxide is also known to stabilize the higher oxidation states of iron, for instance in BaFeOs in which iron has the valence fV [1970Bel, 1971Zan],... 

Pou] Pouillard G., Shamsul A.M., Trinel-Dufour M.C., Perrot P, The Binary System Barium Oxide-Iron(iii) Oxide (Ba0-Fc203) Phase Diagram and Thermodynamic Properties , J. Chem. Res., (5), (5), 136-137, (M), 1720-1747 (1981) (Phase Diagram, Thermodyn., Experimental,, , 40)... 

In general, the chemistry of inorganic lead compounds is similar to that of the alkaline-earth elements. Thus the carbonate, nitrate, and sulfate of lead are isomorphous with the corresponding compounds of calcium, barium, and strontium. In addition, many inorganic lead compounds possess two or more crystalline forms having different properties. For example, the oxides and the sulfide of bivalent lead are frequendy colored as a result of their state of crystallisation. Pure, tetragonal a-PbO is red pure, orthorhombic P PbO is yeUow and crystals of lead sulfide, PbS, have a black, metallic luster. 

Lead zirconate [12060-01 -4] PbZrO, mol wt 346.41, has two colorless crystal stmctures a cubic perovskite form above 230°C (Curie point) and a pseudotetragonal or orthorhombic form below 230°C. It is insoluble in water and aqueous alkaUes, but soluble in strong mineral acids. Lead zirconate is usually prepared by heating together the oxides of lead and zirconium in the proper proportion. It readily forms soHd solutions with other compounds with the ABO stmcture, such as barium zirconate or lead titanate. Mixed lead titanate-zirconates have particularly high piezoelectric properties. They are used in high power acoustic-radiating transducers, hydrophones, and specialty instmments (146). 

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