Beryllium hydroxide, Be(OH)₂, is an

amphoteric In chemistry, an amphoteric compound () is a molecule or ion that can react both as an acid and as a base. What exactly this can mean depends on which definitions of acids and bases are being used. One type of amphoteric species are amphip ...

hydroxide Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water ...

, dissolving in both acids and

alkali In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a basic, ionic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of ...

s. Industrially, it is produced as a by-product in the extraction of beryllium metal from the ores

beryl Beryl ( ) is a mineral composed of beryllium aluminium silicate with the chemical formula Be3Al2Si6O18. Well-known varieties of beryl include emerald and aquamarine. Naturally occurring, hexagonal crystals of beryl can be up to several ...

and bertrandite. The natural pure beryllium hydroxide is rare (in form of the mineral behoite, orthorhombic) or very rare (clinobehoite, monoclinic).Mindat, http://www.mindat.org/min-1066.html When alkali is added to beryllium salt solutions the α-form (a gel) is formed. If this left to stand or boiled, the rhombic β-form precipitates.Mary Eagleson, 1994, Concise encyclopedia chemistry, Walter de Gruyter, This has the same structure as

zinc hydroxide Zinc hydroxide Zn( OH)2 is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal). Like the hydroxides of other metals, such as lead, aluminium, b ...

, Zn(OH)₂, with tetrahedral beryllium centers.

Reactions

Beryllium hydroxide is difficult to dissolve in water. With alkalis it dissolves to form the tetrahydroxoberyllate/tetrahydroxidoberyllate anion, e(OH)₄sup>2−.Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier With

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkal ...

solution: :2 NaOH(aq) + Be(OH)₂(s) → Na₂ e(OH)₄aq) With acids, beryllium salts are formed. For example, with sulfuric acid, H₂SO₄, beryllium sulfate is formed: :Be(OH)₂ + H₂SO₄ → BeSO₄ + 2 H₂O Beryllium hydroxide dehydrates at 400 °C to form the soluble white powder, beryllium oxide: :Be(OH)₂ → BeO + H₂O Further heating at higher temperature produces acid insoluble BeO.

References

{{Hydroxides Amphoteric compounds Beryllium compounds Hydroxides