Lithium arsenate, Li₃AsO₄

The semihydrate, 2Li₃AsO₄,H₂O, is obtained by the action of lithium carbonate on arsenic acid. The anhydrous salt is prepared by recrystallizing this hydrate from fused lithium chloride, its density at 15° C. being 3.07. With excess of arsenic acid the normal salt yields deliquescent prisms of the dihydrogen arsenate, 2LiH₂AsO₄,3H₂O, from which water regenerates the trilithium salt.