Holmium(III) nitrate
# Holmium(III) nitrate

Holmium (III) nitrate is an inorganic compound, a salt of holmium and nitric acid with the chemical formula $Ho(NO_3)_3.$ The compound forms yellowish crystals, dissolves in water, also forms crystalline hydrates.

## Synthesis

Anhydrous salt is obtained by the action of nitrogen dioxide on holmium(III) oxide:

       ${\mathsf {2Ho_{2}O_{3}+9N_{2}O_{4}\ {\xrightarrow {150^{o}C}}\ 4Ho(NO_{3})_{3}+6NO}}$

Effect of nitrogen dioxide on metallic holmium:

       ${\mathsf {Ho+3N_{2}O_{4}\ {\xrightarrow {200^{o}C}}\ Ho(NO_{3})_{3}+3NO}}$

Reaction of holmium hydroxide and nitric acid:

       ${\mathsf {Ho(OH)_{3}+3NHO_{3}\ \xrightarrow {150^{o}C} \ Ho(NO_{3})_{3}+3H_{2}O}}$

## Physical properties

Holmium(III) nitrate forms yellowish crystals.

Forms a crystalline hydrate of the composition $Ho(NO_3)_3•5H_2O.$

Soluble in water and ethanol.

## Chemical properties

Hydrated holmitic nitrate thermally decomposes to form HoONO $_3$ and decomposes to holmium oxide upon subsequent heating.

## Application

The compound is used for the production of ceramics and glass.

Also used to produce metallic holmium and as a chemical reagent.

