Beryllium Arsenates

Monoberyllium arsenate, BeH₄(AsO₄)₂, is obtained as colourless, hygroscopic leaflets after preparation in concentrated solution and evaporation in vacuo. Triberyllium arsenate, Be₃(AsO₄)₂.15H₂O, has been prepared from arsenic oxide and beryllium hydroxide as an amorphous powder. Other arsenates and double arsenates with alkali metals are unstable.