Barium hydroxide (Ba(OH)2 ) when mixed with water (H2O) ionizes completely. Its aqueous solution becomes free of carbonate unlike those of potassium hydroxide and sodium hydroxide.
Therefore, indicators such as thymolphthalein and phenolphthalein can be used in the titration of weak acids without the risk of errors owing to the presence of carbonate ions.
Barium hydroxide is also used to clean up acid spills, neutralize sulfuric acid solutions and decarboxylate amino acids. It is also used as a strong base in organic synthesis, such as the hydrolysis of nitriles and esters.
Barium hydroxide which is a white solid has a boiling point of 780 °C and a melting point of 325° C.