Europium(III) arsenate explained

Europium(III) arsenate is an arsenate salt of europium, with the chemical formula of EuAsO₄. It has good thermal stability, with its pK_sp,c of 22.53±0.03.^[1] It is a colorless crystal with a xenotime structure.

Preparation

Europium(III) arsenate can be prepared by reacting sodium arsenate (Na₃AsO₄) in a europium(III) chloride (EuCl₃) solution:^[2]

Na₃AsO₄ + EuCl₃ → 3 NaCl + EuAsO₄↓

Reacting europium(III) oxide (Eu₂O₃) with arsenic pentoxide (As₂O₅) can also obtain europium(III) arsenate.^[3]

Eu₂O₃ + As₂O₅ → 2EuAsO₄

Notes and References

1. Firsching . F. Henry . Solubility products of the trivalent rare-earth arsenates . Journal of Chemical & Engineering Data . October 1992 . 37 . 4 . 497–499 . 10.1021/je00008a028.
2. Gabisoniya, Ts. D.; Nanobashvili, E. M.. Synthesis of rare earth metal arsenates. Soobshcheniya Akademii Nauk Gruzinskoi SSR (1980), 97(2), 345-8.
3. Golbs. Sylvia. Cardoso-Gil. Raul. Schmidt. Marcus. Crystal structure of europium arsenate, EuAsO4. Zeitschrift für Kristallographie - New Crystal Structures. 224. 2. 2009. 169–170 . 2197-4578. 10.1524/ncrs.2009.0076. 95164970 . free.