This allows the use of indicators such as phenolphthalein or thymolphthalein (with alkaline colour changes) without the risk of titration errors due to the presence of carbonate ions, which are much less basic.

There are several uses for barium hydroxide such as to hydrolyse one of the two equivalent ester groups in dimethyl hendecanedioate.

Its aqueous solution, being highly alkaline, undergoes neutralization reactions with acids.

Precipitation of many insoluble, or less soluble barium salts, may result from double replacement reaction when a barium hydroxide aqueous solution is mixed with many solutions of other metal salts.

[17] Reactions of barium hydroxide with ammonium salts are strongly endothermic.

The reaction of barium hydroxide octahydrate with ammonium chloride[18][19] or[20] ammonium thiocyanate[20][21] is often used as a classroom chemistry demonstration, producing temperatures cold enough to freeze water and enough water to dissolve the resulting mixture.