Barium metal reactions with

Barium metal is produced commercially by the reduction of barium oxide with a less reactive, nonvolatile element, usually aluminum (16—22). Depending on initial stoichiometry, two overall reactions occur in the BaO reduction ... 

The barium crowns are usually broken into smaller pieces and can be sold in this form or cast or extmded into bars or wire. Usually the metal is packaged in argon-fiked plastic bags inside argon-fiked steel containers. Barium is classed as a flammable soHd and cannot be mailed. It should be stored in a wek-ventilated area so as to remove any hydrogen formed through reaction with water vapor. It should not be stored where contact with water is possible. 

Barium metal and most barium compounds are highly poisonous. A notable exception is barium sulfate which is nontoxic because of its extreme iasolubihty ia water. Barium ion acts as a muscle stimulant and can cause death through ventricular fibrillation of the heart. Therefore, care must be taken to avoid contact with open areas of the skin. Workers must wear respirators (of type approved for toxic airborne particles), goggles, gloves, and protective clothing at all times. The toxic barium aluminate residue obtained from barium production is detoxified by reaction with a solution of ferrous sulfate and converted iato nontoxic barium sulfate. According to OSHA standards, the TWA value for Ba and Ba compounds ia air is 0.5 mg/m. ... 

From microscopic measurements of the rates of nucleation and of growth of particles of barium metal product, Wischin [201] observed that the number of nuclei present increased as the third power (—2.5—3.5) of time and that the isothermal rate of radial growth of visible nuclei was constant. During the early stages of reaction, the acceleratory region of the a—time plot obeyed the power law [eqn. (2)] with 6 temperature coefficients of these processes were used by Wischin [201]... 

A violent reaction occurred when cleaning lump metal under carbon tetrachloride [1], Finely divided barium, slurried with trichlorotrifluoroethane, exploded during transfer owing to frictional initiation [2], Granular barium in contact with fluo-rotrichloromethane, carbon tetrachloride, 1,1,2-trichlorotrifluoroethane, tetrachloro-ethylene or trichloroethylene is suceptible to detonation [3]. Thermodynamic calculations indicated a heat of decomposition of 2.60 kJ/g of mixture and a likely adiabatic temperature approaching 3000°C, accompanied by a 30-fold increase in pressure [4],... 

An aqueous solution of periodic acid, free from metal ions, may be prepared through the conversion of potassium metaperiodate to the slightly soluble barium dimesoperiodate, Ba2l207, which, through reaction with an equivalent amount of sulfuric acid, yields pure periodic acid.107 Hudson found that nitrate as an impurity in periodic acid gives rise to erroneous results in this field.239 ... 

Barium metal reacts exothermically with oxygen at ambient temperatures forming harium oxide. The reaction is violent when the metal is present in powder form. It also reacts violently with water forming harium hydroxide and liberating hydrogen ... 

Barium acetate converts to barium carbonate when heated in air at elevated temperatures. Reaction with sulfuric acid gives harium sulfate with hydrochloric acid and nitric acid, the chloride and nitrate salts are obtained after evaporation of the solutions. It undergoes double decomposition reactions with salts of several metals. For example, it forms ferrous acetate when treated with ferrous sulfate solution and mercurous acetate when mixed with mercurous nitrate solution acidified with nitric acid. It reacts with oxahc acid forming barium oxalate. 

Barium hydroxide decomposes to barium oxide when heated to 800°C. Reaction with carbon dioxide gives barium carbonate. Its aqueous solution, being highly alkahne, undergoes neutrahzation reactions with acids. Thus, it forms barium sulfate and barium phosphate with sulfuric and phosphoric acids, respectively. Reaction with hydrogen sulfide produces barium sulfide. Precipitation of many insoluble, or less soluble barium salts, may result from double decomposition reaction when Ba(OH)2 aqueous solution is mixed with many solutions of other metal salts. 

In an atmosphere of nitric oxide, thermal decomposition produces barium nitrite, Ba(N02)2. Reactions with soluble metal sulfates or sulfuric acid yield barium sulfate. Many insoluble barium salts, such as the carbonate, oxalate and phosphate of the metal, are precipitated by similar double decomposition reactions. Ba(N03)2 is an oxidizer and reacts vigorously with common reducing agents. The solid powder, when mixed with many other metals such as aluminum or zinc in their finely divided form, or combined with alloys such as... 

Metals and Sulphates. — 20 cc. portions of the 1 20 aqueous solution should afford no reaction with either hydrogen sulphide water or barium chloride solution. 

Bacteriochlorins, 851 Barbituric acid metal complexes, 798 Barium alkoxides synthesis, 336 Barium complexes phthalocyanines, 863 porphyrins, 820 Becium homblei copper accumulation, 964 Benzaldehyde, 2-amino-self-condensation aza macrocycles from, 900 Benzamide, o-mercapto-metal complexes, 655 Benzamide oximes metal complexes, 274 Benzamidine, /V, V -diphenyl-metal complexes. 275 Benzene, 1,2-diamino-reactions with dicarbonyl compounds aza macrocycles from, 902 Benzene, 4 methylthionitroso-metal complexes, 804 Benzenedithiolates metal complexes, 605... 

These are usually reactions of anhydrous transition and B metal halides with dry alkali metal salts such as the sulphides, nitrides, phosphides, arsenides etc. to give exchange of anions. They tend to be very exothermic with higher valence halides and are frequently initiated by mild warming or grinding. Metathesis is described as a controlled explosion. Mixtures considered in the specific reference above include lithium nitride with tantalum pentachloride, titanium tetrachloride and vanadium tetrachloride, also barium nitride with manganese II iodide, the last reaction photographically illustrated. 

---