Beryllium hydroxide
Encyclopedia
Beryllium hydroxide, Be(OH)2 is an amphoteric hydroxide
, dissolving in both acids and alkali
s. Industrially it is produced as a by-product in the extraction of beryllium metal from the ores, beryl
and bertrandite
. 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. This has the zinc hydroxide
, Zn(OH)2 structure with tetrahedral beryllium centers.
With acids, beryllium salts are formed. For example, with sulfuric acid
, H2SO4, beryllium sulfate
is formed:
Beryllium hydroxide dehydrates at 400 °C to form the soluble white powder, beryllium oxide
:
Further heating at higher temperature produces acid insoluble BeO.
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and a hydrogen atom held together by a covalent bond, and carrying a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, as a ligand, a nucleophile, and a...
, dissolving in both acids and alkali
Alkali
In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...
s. Industrially it is produced as a by-product in the extraction of beryllium metal from the ores, beryl
Beryl
The mineral beryl is a beryllium aluminium cyclosilicate with the chemical formula Be3Al26. The hexagonal crystals of beryl may be very small or range to several meters in size. Terminated crystals are relatively rare...
and bertrandite
Bertrandite
Bertrandite is a beryllium sorosilicate hydroxide mineral with composition: Be4Si2O72. Bertrandite is a colorless to pale yellow orthorhombic mineral with a hardness of 6-7. It is commonly found in beryllium rich pegmatites and is in part an alteration of beryl. Bertrandite often occurs as a...
. 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. This has the zinc hydroxide
Zinc hydroxide
Zinc hydroxide Zn2 is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite , ashoverite and sweetite ....
, Zn(OH)2 structure with tetrahedral beryllium centers.
Reactions
With alkalis it dissolves to form the tetrahydroxidoberyllate(2-) anion. With sodium hydroxide solution:- 2NaOH(aq) + Be(OH)2(s) → Na2Be(OH)4(aq)
With acids, beryllium salts are formed. For example, with sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
, H2SO4, beryllium sulfate
Beryllium sulfate
Beryllium sulfate is a white crystalline solid. It was first isolated in 1815 by Jons Jakob Berzelius.Beryllium sulfate may be prepared by treating an aqueous solution of any beryllium salt with sulfuric acid, followed by evaporation of the solution and crystallization...
is formed:
- Be(OH)2 + H2SO4 → BeSO4 + 2H2O
Beryllium hydroxide dehydrates at 400 °C to form the soluble white powder, beryllium oxide
Beryllium oxide
Beryllium oxide , also known as beryllia, is an inorganic compound with the formula BeO. This colourless solid is a notable electrical insulator with a higher thermal conductivity than any other non-metal except diamond, and actually exceeds that of some metals. As an amorphous solid, beryllium...
:
- Be(OH)2 → BeO + H2O
Further heating at higher temperature produces acid insoluble BeO.