Yttrium hydroxide, Y(OH)₃

Yttrium hydroxide, Y(OH)₃, is obtained as a gelatinous precipitate from solutions of yttrium salts by the addition of excess of a soluble hydroxide. It readily absorbs carbon dioxide. When the precipitant is a mixture of ammonia and hydrogen peroxide, hydrated yttrium peroxide, Y₄O₉.xH₂O or perhaps Y₂O₅.xH₂O, is produced.