Perceric hydroxide

Perceric hydroxide, CeO₃.xH₂O or Ce(OH)₃.O.OH. - When a cerous salt is treated with a mixture of ammonia and hydrogen peroxide, a reddish-brown, gelatinous precipitate of perceric hydroxide is obtained, which has the composition of a hydrated trioxide, CeO₃.xH₂O. According to Pissarjewsky, the precipitate is produced as follows: -

Ce(OH)₄ + HO.OH = Ce(OH)₃.O.OH + H₂O.

It is an unstable compound, losing oxygen fairly quickly even at the ordinary temperature. It is rapidly converted into ceric hydroxide when heated with boiling water or when dried at 120°. It dissolves in dilute mineral acids, producing a cerous salt, hydrogen peroxide, and oxygen, e.g.: -

2Ce(OH)₃.O.OH + 3H₂SO₄ = Ce₂(SO₄)₃ + H₂O₂ + O₂ + 6H₂O.