Chemical elements
    Physical Properties
    Chemical Properties
      Barium Hydride
      Barium Subfluoride
      Barium Fluoride
      Acid Barium Fluoride
      Barium Subchloride
      Barium Chloride
      Barium Bromide
      Barium Perbromides
      Barium Iodide
      Barium Periodides
      Barium Mixed Halides
      Barium Mixed Perhalides
      Barium Oxychloride
      Barium Hypochlorite
      Barium Chlorite
      Barium Chlorate
      Barium Perchlorate
      Barium Oxybromide
      Barium Hypobromite
      Barium Bromate
      Barium Perbromate
      Barium Oxyiodide
      Barium Iodate
      Barium Periodate
      Barium Manganites
      Barium Manganate
      Barium Permanganate
      Barium Suboxide
      Barium Oxide
      Barium Hydroxide
      Barium Peroxide
      Barium Peroxyhydrate
      Barium Tetroxide
      Barium Sulphide
      Barium Hydrosulphide
      Barium Polysulphides
      Barium Hydroxyhydrosulphide
      Barium Oxysulphides
      Barium Sulphite
      Barium Thiosulphate
      Barium Dithionate
      Barium Trithionate
      Barium Tetrathionate
      Barium Pentathionate
      Barium Sulphate
      Acid Barium Sulphates
      Barium Pyrosulphate
      Barium Persulphate
      Barium Selenide
      Barium Selenite
      Barium Selenate
      Acid Barium Selenate
      Barium Telluride
      Barium Tellurite
      Barium Tellurate
      Barium Chromite
      Barium Chromate
      Barium Dichromate
      Barium Potassium Trichromate
      Barium Chlorochromate
      Barium Perchromate
      Barium Molybdate
      Barium Permolybdate
      Barium Tungstate
      Barium Uranate
      Barium Diuranate
      Barium Peruranate
      Barium Nitride
      Barium Azide
      Barium Hexammoniate
      Barium Ammonium
      Barium Amide
      Barium Amidosulphonate
      Barium Imide
      Barium Imidosulphonate
      Barium Hyponitrite
      Barium Nitroxysulphite
      Barium Nitrososulphate
      Barium Nitrohydroxylaminate
      Barium Nitrite
      Barium Nitrate
      Barium Phosphide
      Barium Dihydrohypophosphite
      Barium Hydrophosphite
      Barium Hypophosphate
      Barium Orthophosphates
      Barium Pyrophosphate
      Barium Metaphosphate
      Basic Barium Phosphates
      Barium Thiophosphites
      Barium Thiophosphates
      Barium Selenophosphates
      Barium Azophosphates
      Barium Phosphimates
      Barium Arsenide
      Barium Orthoarsenite
      Barium Pyroarsenite
      Barium Orthoarsenates
      Barium Pyroarsenate
      Barium Thioarsenites
      Barium Thioarsenates
      Barium Sodium Selenoxyarsenate
      Barium Metantimonate
      Barium Thioantimonites
      Barium Chloroantimonite
      Barium Orthothioantimonate
      Barium Hypovanadate
      Barium Vanadates
      Barium Metapervanadate
      Barium Niobate
      Barium Tantalate
      Barium Pertantalate
      Barium Carbide
      Barium Carbonyl
      Barium Formate
      Barium Acetate
      Barium Oxalate
      Barium Carbonate
      Barium Thiocarbonate
      Barium Percarbonate
      Barium Cyanide
      Barium Cyanamide
      Barium Cyanate
      Barium Cyanurate
      Barium Thiocyanate
      Barium Selenocyanate
      Barium Silicide
      Barium Silicates
      Barium Fluosilicate
      Barium Stannate
      Barium Orthoplumbate
      Barium Titanate
      Barium Peroxide Pertitanate
      Barium Pertitanate
      Barium Fluoroxytitanate
      Barium Zirconate
      Barium Boride
      Barium Borates
      Barium Fluorborate
      Barium Perborate
      Barium Aluminates
      Barium Ferrite
      Barium Ferrate
      Barium Gobaltite
      Barium Dinickelite
      Barium Platinate
    Detection of Barrium
    PDB 1djh-3iqp
    PDB 3iqr-4e7y

Barium Oxide, BaO

Barium Oxide, BaO, may be formed by the direct combination of its elements. It is obtained by calcination of the hydroxide or nitrate. A high temperature is required to prevent contamination with the peroxide. Barium carbonate cannot be decomposed under the conditions prevailing in the limekiln. For production from witherite on the commercial scale it is necessary to heat with carbon, when the following reaction takes place: -

BaCO3 + C = BaO + 2CO.

According to a patent of Frank's, barium oxide may be obtained by heating together barium carbonate and carbide.

3BaCO3 + BaC2 = 4BaO + 5CO.

Barytes may be used instead of witherite, and is generally a purer mineral. By heating with coal or coke in the reverberatory furnace, or preferably by using a gaseous reducing agent at 600°-650° C., barytes may be reduced to the sulphide, which can be readily converted into the hydroxide and thence into the oxide.

The United Barium Company at Niagara Falls patented a process for preparing barium oxide directly from barium sulphate. The sulphate is mixed with sufficient carbon to reduce a quarter of the sulphate to sulphide, and the whole is heated in the electric furnace. The following reactions take place: -

BaSO4 + 4C = BaS + 4CO BaS + 3BaSO4 = 4BaO + 4SO2.

By heating barium chloride with zinc oxide at white heat, zinc chloride is made to volatilise and barium oxide is left.

Barium hydroxide may be prepared electrolytically and then converted into the oxide.

As ordinarily produced, it is a white (or often greyish) amorphous powder, the density of which varies considerably, from 4.78 – 5.76, with the method of production. It may be obtained in a crystalline form by slow calcination of the nitrate, but, owing probably to the fact that, unlike calcium and strontium oxides, barium oxide does not dissolve in the nitrate, the crystals are only microscopic. There are apparently two forms, cubic, of density 5.74, and hexagonal, of density 5.32. By fusing in the electric furnace at a lower temperature than is possible in the case of calcium or strontium oxides, and allowing to cool, a crystalline mass is obtained. Barium oxide also crystallises out when a mixture of barium and lithium carbonates is heated to 1150°-1250° C. The heat of formation of barium oxide is 125.86 Cal. Hydrochloric acid reacts with barium oxide even at ordinary temperatures, probably owing to the difficulty of making it completely anhydrous. Sulphuretted hydrogen and sulphur dioxide only react when heated. By heating with carbon dioxide the reaction is so vigorous that the product becomes incandescent and may reach a temperature of 1200° C. A basic carbonate of indefinite composition results.

Investigations of the temperature of dehydration of hydrated barium hydroxide have led de Forcrand to the conclusion that barium oxide should be represented as a condensed product, (BaO)n.

In the presence of small quantities of phosphorogens, barium oxide is phosphorescent.

Barium oxide dissolves in fused barium chloride to the extent of one molecule of oxide to one of chloride. Mixed crystals containing 17.7 per cent, of oxide separate out.

Owing to its tendency to form barium peroxide, the oxide may be used as a reducing agent for organic compounds.

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