Thulium(III) nitrate
# Thulium(III) nitrate

Thulium(III) nitrate is an inorganic compound, a salt of thulium and nitric acid with the chemical formula $Tm(NO_3)_3.$ The compound forms dark-green crystals, readily soluble in water, also forms crystalline hydrates.

## Synthesis

Reaction of thulium and nitric acid:

       Tm + $6HNO_3$ → $Tm(NO_3)_3$ + $3NO_2$ + $3H_2O$

Reaction of thulium hydroxide and nitric acid:

       $Tm(OH)_3$ + $3HNO_3$ → $Tm(NO_3)_3$ + $3H_2O$

## Physical properties

Thulium(III) nitrate forms dark-green hygroscopic crystals.

Forms crystalline hydrates of the composition $Tm(NO_3)_3·5H_2O.$

Soluble in water and ethanol.

## Chemical properties

Both the compound and its crystalline hydrate decompose on moderate heating.

Hydrated thulium nitrate thermally decomposes to form $TmONO_3$ and decomposes to thulium oxide upon further heating.

## Applications

Thulium(III) nitrate hydrate is used as a reagent. Also used in optical glasses, ceramics, catalysts, electrical components, and photo-optical materials.

