Barium arsenide

On the basis of the expected charges on the monatomic ions, give the chemical formula of each of the following compounds (a) manganese(II) telluride (b) barium arsenide ... 

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. 

When arsine is passed over a heated metal, such as the alkali and alkaline earth metals, zinc or tin, the decomposition of the gas is accelerated and the arsenide of the metal is formed. If platinum is used, the removal of arsenic from the gas is complete.3 The action of sodium or potassium on arsine in liquid ammonia yields 4 the dihydrogen arsenide (MHgAs). Heated alkali hydroxides in the solid form quickly decompose the gas, forming arsenites, and at higher temperatures arsenates and arsenides of the metals.5 The aqueous and alcoholic solutions have no appreciable action.6 When the gas is passed over heated calcium oxide the amount of decomposition is not more than that due to the action of heat alone. Heated barium oxide, however, is converted into a dark brown mixture of barium arsenite and arsenate, hydrogen being liberated.7 The gas is absorbed by soda-lime.8... 

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. 

Volclay 351CER Volclay HPM-75 Volclay KWK 200 Volclay KWK Food Grade Volclay NF-BC Xtra Gel 215-114-8 Gallium arsenide 215-125-8 Boron oxide 215-127-9 Barium oxide 215-128-4 Barium peroxide 215-134-7 Bismuth oxide 215-135-2 Bismuth telluride 215-136-8 Bismuth subnitrate 215-137-3 Calcium hydroxide Calcium Hydroxide BC 802 Calcium Hydroxide HP Fluorox E... 

The material composition of the FPAs determines the detectable IR-spectral frequency range. Many types of detectors are available, ranging from the commonly used indium antimonide (InSb) for near IR and mercury cadmium telluride (HgCdTe, MCT) for the mid IR to the more exotic silicon arsenide (Si As) [10] and uncooled barium strontium titanium (BST) [11]. Mid-IR imaging using MCT FPAs [12] has been the most popular in terms of the number of studies performed, due to its ability to provide access to the molecular-fingerprint region. 

Barium fluoride (Fp. 1355 °C solubility in water 1 g/1 at 20 °C) is used in aluminium metallurgy, in enamel and glazing frits and in the production of arc welding agents. Single crystal barium fluoride is employed in combination with gallium arsenide as insulator for semiconductor devices [62]. Bap2 can be synthesized by precipitation in a reaction of a water-soluble barium salt with aqueous HF. 

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