3.3 g of neodymium(III) oxide is suspended in 20 mL of water whereto 7.5 mL of conc. nitric acid is added with stirring. The solution is then evaporated down to 10 mL with a hot plate, subsequently dried in a vacuum desiccator over a drying agent. The compound is very hygroscopic, thus should be stored in an air-tight container.
Nd2O3 + 6 HNO3 = 2 Nd(NO3)3 + 3 H2O
Evaporation of water after addition
Drying with a desiccator
The pure product