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Barium Hydroxide

Author: Hans Lohninger

Barium hydroxide, Ba(OH)2, is also known as baryta. It can be prepared either by dissolving barium oxide (BaO) or barium sulfide (BaS) in water:

BaO + H2O Ba(OH)2 + H2O
BaS + H2O Ba(OH)2 + H2S

Barium hydroxide crystallizes as the octahydrate, Ba(OH)28H2O, which can be converted to the monohydrate by heating in air. The white granular monohydrate is the usual commercially available form. Barium hydroxide decomposes to barium oxide when heated to 800C.

Barium hydroxide forms an alkaline solution in water ("baryta water") which can be used to titrate weak acids, since its clear aqueous solution is guaranteed to be free of carbonate (barium carbonate is insoluble in water).

Last Update: 2011-02-16