Yttrium nitrate, Y(NO₃)₃

The system Y2O3 - N2O5 - H20 at 25° C. Solubility diagram.

Yttrium nitrate, Y(NO₃)₃.6H₂O, forms deliquescent, triclinic crystals and loses 3H₂O at 100°. The trinitrate, Y(NO₃)₃.3H₂O, crystallises from very concentrated nitric acid. A dihydrate has also been described. When heated, yttrium nitrate first forms basic nitrate and subsequently at very high temperatures leaves a residue of yttria. Yttrium nitrate is isodimorphous with bismuth nitrate.

A saturated aqueous solution of the nitrate at 25° has a specific gravity (25°/25°) of 1.7446 and contains 141.6 grams of anhydrous nitrate per 100 grams of water.

The only basic yttrium nitrate that exists at 25° has the composition 3Y₂O₃.4N₂O₅.20H₂O. It is stable in air and in the presence of a solution of yttrium nitrate containing one-fourth its weight or more of anhydrous nitrate, and from such a solution it can be recrystallised (see fig.). It is not affected by absolute alcohol, but is decomposed by water.