Barium Hydroxide (Anhydrous)

DescriptionBarium hydroxide is a kind of barium base. It has many kinds of applications. It can be used as the precursor for the preparation of other barium compounds. Its monohydrate form can be used to dehydrate and remove sulfate in many products. In laboratory, it can be used in analytic chemistry for the titration assay of organic acid. In organic synthesis, it is a strong base used for the hydrolysis of esters and nitriles. It is also a useful catalyst of organic synthesis. Other applications also include acting as an interlayer between zinc oxide and a luminescent conjugated polymer for light-emitting diodes, extracting pure arabinoxylans from water-insoluble cell wall material of wheat flour, removing sulfate and metals from the water and acting as a selective precipitating agent for hemicelluloses.

UsesBarium hydroxide, especially the monohydrate, is used to produce organic barium compounds such as additives for oil and stabilizers for plastics. In addition, barium hydroxide is used for. dehydration and deacidification, especially for removing sulfuric acid from fats, oils, waxes, and glycerol. In some applications, e.g., removal of sulfate from water and as starting material for other barium compounds, barium hydroxide to some ex1ent replaces barium carbonate. The earlier use of the hydroxide in some countries forextracting the residual sucrose from molasses is no longer of much significance. The re- cent patent literature describes a procedure in which barium hydroxide is reacted with hydrogen peroxide to produce barium peroxide monohydrate.

DescriptionBarium Hydroxide occurs as an anhydrate whose prismatic, colorless crystals are very deliquescent. Barium hydroxide can be prepared by dissolving barium oxide (BaO) in water: BaO＋ 9H2O→Ba(OH)2·8H2O It crystallizes as the octahydrate, which converts to the monohydrate upon heating in air. Barium oxide has been found to react with water vapor at temperatures from 1443 to 1593 K to form gaseous Ba(OH)2 according to the reaction: BaO(solid)＋H2O(gas)→Ba(OH)2(gas) A better method of preparation involves addition of NaOH to the nitrate. Since barium hydroxide is fairly soluble, it is necessary to evaporate the solution to crystallize Ba(OH)2·8H2O. Ethanol is added to aid in this crystallization. The crystals are washed in cold ethanol to remove sodium ions and then dried.

UsesBarium hydroxide is used in analytical chemistry to titrate weak acids, particularly organic acids. It forms clear aqueous solutions that are free from carbonate, unlike those of the alkali hydroxides, since barium carbonate is insoluble in water. This allows the use of indicators such as phenolphthalein or thymophthalein (with alkaline color changes) without the risk of titration errors due to the presence of weakly basic CO32- ions.Barium hydroxide is used in organic synthesis as a strong base, for example for the hydrolysis of esters and nitriles.It has been used to hydrolyze one of the two equivalent ester groups in dimethyl endecanedioate. It is also used in the preparation of cyclopentanone, diacetone alcohol and d-Gluonic g-lactone. Barium hydroxide is used as an additive in thermoplastics (such as phenolic resins), rayon and PVC stabilizers to improve plastic properties. This material is used as a general-purpose additive for lubricants and greases. Other industrial applications for barium hydroxide include sugar fabrication, manufacturing soaps, fat saponification, fusing of silicates and chemical synthesis of other barium compounds and organic compounds. Barium hydroxide is offered for sale both as the octahydrate and the monohydrate. It is available in large quantities commercially.