Important beryllium compounds

Beryllium carbonate (BeCO₃) , molecular weight: 69.021 g/mol , melting point: 54 °C  .
It is An unstable solid prepared by prolonged treatment of a suspension of beryllium hydroxide with carbon dioxide. The resulting solution is evaporated and filtered in an atmosphere of carbon dioxide. This compound is toxic, Irritant and dangerous for the environment.

Beryllium chloride (BeCl₂), molecular weight 79.9182 g/mol , density 1.899 g/cm², melting point 399 °C . It is a white solid obtained by passing chlorine over a heated mixture of beryllium oxide and carbon. It is a poor conductor in the fused state and in the solid form consists of a covalent polymeric structure. It is readily soluble in organic solvents but is hydrolyzed in the presence of water to give the hydroxide. The anhydrous salt is used as a catalyst.

Beryllium hydrogencarbonate (beryllium bicarbonate; Be(HCO₃)₂) molecular weight 131.046 g/mol . It is a A compound formed in solution by the action of carbon dioxide on a suspension of the carbonate, to which it reverts on heating:
BeCO₃ + CO₂ + H₂O → Be(HCO3)2

Beryllium hydroxide (Be(OH)₂) molecular weight 43.03 g/mol , density 1.92 g/cm3, melting point 1,000 °C . It is a solid that can be precipitated from beryllium- containing solutions by an alkali. In an excess of alkali, beryllium hydroxide dissolves to give a beryllate, Be(OH)₄²⁻. In this way, beryllium and aluminum hydroxides are similar and the reaction is an indication that beryllium hydroxide is amphoteric. It is very toxic, harmful and dangerous for the environment.

Beryllium oxide (BeO) molecular weight 25.01 g/mol , density 3.01 g/cm³, melting point 2,507 °C . It is a white solid formed by heating beryllium in oxygen or by the decomposition of beryllium hydroxide or carbonate. Beryllium oxide is insoluble in water but it shows basic properties by dissolving in acids to form beryllium salts:

BeO + 2H⁺ → Be²⁺ + H2O

However, beryllium oxide also resembles acidic oxides by reacting with alkalis to form beryllates:

BeO + 2OH⁻ + H₂O → Be(OH)₄²⁻

It is thus an amphoteric oxide. Beryllium oxide is used for the production of beryllium and beryllium-copper refractories, for high-output transistors, and for printed circuits. The chemical properties of beryllium oxide are similar to those of aluminum oxide. It is very toxic, harmful and dangerous for the environment.

Beryllium sulfate (BeSO₄) molecular weight 105.075 g/mol , density 2.44 g/cm³, melting point 110 °C . It's an insoluble salt prepared by the reaction of beryllium oxide with concentrated sulfuric acid. On heating, it breaks down to give the oxide. When heated in the presence of water, it readily dissolves to give an acidic solution. It is very toxic, harmful and dangerous for the environment.