Ammonia solution
Ammonia solution, also known as ammonia water, ammonium hydroxide, ammoniacal liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or (inaccurately) ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH(aq). Although the name ammonium hydroxide suggests an alkali with composition [NH][OH], it is actually impossible to isolate samples of NHOH. The ions NH and OH do not account for a significant fraction of the total amount of ammonia except in extremely dilute solutions.
Aluminium hydroxide
Gibbsite is also known as hydrargillite, named after the Greek words for water (') and clay ('). The first compound named "hydrargillite" was thought to be aluminium hydroxide, but was later found to be aluminium phosphate; despite this, both "gibbsite" and "hydrargillite" are used to refer to the same polymorphism of aluminium hydroxide, with "gibbsite" used most commonly in the United States and "hydrargillite" used more often in Europe. In 1930, it was referred to as "α-alumina trihydrate" to contrast it with bayerite, which was called "β-alumina trihydrate" (the alpha and beta designations were used to differentiate the more- and less-common forms respectively). In 1957, a symposium on alumina nomenclature attempted to develop a universal standard, resulting in gibbsite being designated γ-Al(OH), bayerite becoming α-Al(OH), and nordstrandite being designated Al(OH). Based on their crystallographic properties, a suggested nomenclature and designation is for gibbsite to be α-Al(OH), bayerite to be designated β-Al(OH), and both nordstrandite and doyleite are designated Al(OH). Under this designation, the α and β prefixes refer to hexagonal, close-packed structures and altered or dehydrated polymorphisms respectively, with no differentiation between nordstrandite and doyleite.