What is the aluminum hydroxide formula?
Aluminium hydroxide, Al(OH)3, Alum, is the most stable form of
aluminum in normal conditions. It is found in nature as the mineral
gibbsite (also known as hydrargillite) and its three, much more
rare, polymorphs: bayerite, doyleite and nordstrandite. Closely
related are aluminum oxide hydroxide, AlO(OH), and aluminum oxide,
Al2O3, differing only by loss of water. These compounds together
are the major components of the aluminum ore bauxite. Freshly
precipitated aluminum hydroxide forms gels, which is the basis for
application of aluminum salts as flocculants in water purification.
This gel crystallizes with time. Aluminium hydroxide gels can be
dehydrated (e.g., with the utility of water-miscible non-aqueous
solvents like ethanol) to form an amorphous aluminum hydroxide
powder, which is readily soluble in acids. Heat-dried aluminum
hydroxide powder is known as activated alumina and is used in gas
purification, as a catalyst support and an abrasive.